Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays
Open accessAbstract
This study presents a soft, smart contact lens that provides real-time sensing for diabetes through a wireless display.
AI snapshot
Written from the paper’s full text.
TL;DR
A soft, smart contact lens integrates a transparent/stretchable antenna, rectifier, glucose sensor, and LED pixel to wirelessly detect tear glucose and display threshold status. In a live rabbit, glucose above 0.9 mM turned off the LED, with stable operation and no significant heating.
Key findings
- The hybrid substrate matched refractive indices (Δn = ~0.003), giving ~93% transmittance and ~1.6% haze at 550 nm, with oxygen permeability Dk of 340.0 U and >96.7% elastic area.
- Electrospun Ag nanofiber electrodes achieved ~0.3 ohm/sq at 72% transmittance or ~1.3 ohm/sq at 90%, with ~30% stretchability; the antenna showed 21.5% power transfer efficiency at 50 MHz and 5 mm.
- The graphene glucose sensor with GOD/CAT had a response time of ~1.3 s, sensitivity of ~−22.72%/mM, SNR of 23.87 at 0.1 mM, and minimum detectable concentration of ~12.57 μM; it remained stable after 48 hours and 5000 stretch cycles at 30% strain.
- In vivo rabbit testing showed the LED turned off when tear glucose exceeded 0.9 mM; lens temperature stayed ~37°C, and simulated maximum SAR was 1.399 W/kg versus the 10 W/kg regulation value.
Methods
- Fabrication used a hybrid substrate with photocurable optical polymer reinforced islands embedded in silicone elastomer (elastofilcon A), a Cu sacrificial layer, electrospun AgNF antenna/interconnects, Si-diode/capacitor rectifier, LED pixel, and a graphene glucose sensor functionalized with glucose oxidase and catalase.
- Characterization included stretching tests, optical transmittance/haze measurements, electrical and rectifier tests, glucose response in buffered and artificial tear solutions, and stability tests over 48 hours and 5000 cycles.
- In vivo testing used a male New Zealand white rabbit under UNIST IACUC approval (UNISTIACUC-16-19), with wireless operation and infrared temperature monitoring.
Limitations
- Stated: the LED turns off when high glucose is detected, which the authors call counterintuitive and suggest future design improvements for more intuitive status display.
- Evident from the text: in vivo validation was limited to one rabbit, with no human trials reported; stability was tested only up to 48 hours and 5000 cycles.
- Evident from the text: operation required an external transmitting coil at short range (5 mm in tests; transmission distance <9 mm), and the threshold was fixed at 0.9 mM in the circuit, though the authors note it can be tuned by changing sensor resistance.
Model-written summary. Check it against the paper before relying on it.
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Cites
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Claims the paper makes
0 of 33 cited sources checked · 0 supported · 0 flagged
- Findingnone given
The planar, mesh-like structures of the device components and their interconnects enable high stretchability for the curved soft lens with no buckling.
“The planar, mesh-like structures of the components of the device and their interconnects enable high stretchability for the curved soft lens with no buckling.”
Quote in the paperNot a substantial claim - Findingreasoning
These lenses provide superb reliability because they can undergo the mechanical deformations required to fit them into the soft lens without damage.
“In addition, these lenses provide superb reliability because they can undergo the mechanical deformations required to fit them into the soft lens without damage.”
Quote in the paperSubstantial claim - Findingnone given
A soft, smart contact lens can provide real-time sensing for diabetes through a wireless display.
“This study presents a soft, smart contact lens that provides real-time sensing for diabetes through a wireless display.”
Quote in the paperNot a substantial claim - Findingnone given
The hybrid substrate is composed of heterogeneous materials with negligible deviations in the refractive indices of the reinforced parts and the elastomer (Δn = ~0.003).
“Thus, our hybrid substrate is composed of heterogeneous materials with negligible deviations in the refractive indices of the reinforced parts and the elastomer (Δn = ~0.003).”
Quote in the paperSubstantial claim - Findingreasoning
The power transfer circuit can wirelessly receive power with ac signals using the transparent and stretchable inductive antenna.
“This power transfer circuit can wirelessly receive the power with ac signals using this antenna.”
Quote in the paperSubstantial claim
- Findingown data
In vivo tests using a live rabbit demonstrated reliable operation of the smart contact lens without noticeable adverse effects.
“Furthermore, in vivo tests using a live rabbit demonstrated its reliable operation without noticeable adverse effects.”
Quote in the paperSubstantial claim- Rests on an assumption: The live rabbit is a representative model for the human eye for safety and reliable operation of the smart contact lens.
- Findingnone given
After a graphene sensor detects glucose concentration in tears, the transparent and stretchable antenna with a rectifier drives LED pixels to display real-time sensing information wirelessly.
“(iii) For wireless display pixels to visualize glucose levels in real time, after a graphene sensor detects the glucose concentration in the tears, the transparent and stretchable antenna with a rectifier drives the pixels of the light-emitting diode (LED) to display real-time sensing information wirelessly.”
Quote in the paperSubstantial claim - Findingcitation
One-dimensional ultralong metal nanofibers directly electrospun as continuous networks create transparent and stretchable electrodes.
“Thus, one-dimensional (1D), ultralong metal nanofibers (mNFs) were directly electrospun as continuous networks to create transparent and stretchable electrodes (33).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [33] Jang J., Hyun B. G., Ji S., Cho E., An B. W., Cheong W. H., Park J.-U., Rapid production of large-area, transparent and stretchable electrodes using metal nanofibers as wirelessly operated wearable heaters. NPG Asia Mater. 9, e432 (2017). source
Not checked in the free run.
- Findingown data
There were no gaps at the interfaces between the heterogeneous regions even during stretching states (30% in tensile strain).
“In addition, Fig. 2B shows that there were no gaps at the interfaces between these heterogeneous regions even during the stretching states (30% in tensile strain).”
Quote in the paperSubstantial claim - Findingown data
The hybrid substrate preserved its transmittance and haze against mechanical stretching (from 0 to 30% in tensile strain).
“In addition, the hybrid substrate preserved its transmittance and haze against its mechanical stretching (from 0 to 30% in tensile strain) (fig. S4).”
Quote in the paperSubstantial claim - Findingnone given
Exposure to tear fluid with a glucose concentration above the threshold induces a reduction in the sensor resistance.
“Exposure to tear fluid with a glucose concentration above the threshold induces a reduction in the sensor resistance.”
Quote in the paperSubstantial claim - Findingreasoning
Under the constantly applied voltage condition, the bias applied to the parallel circuit of the LED and sensor reduces.
“The bias applied to the parallel circuit of the LED and sensor reduces under the constantly applied voltage condition.”
Quote in the paperSubstantial claim - Findingnone given
The electrospun mNF networks exhibit outstanding stretchability (~30% in tensile strain).
“In addition, they also exhibit the outstanding stretchability (~30% in tensile strain), so they can be suitable as electrodes for interconnects in soft, smart contact lenses.”
Quote in the paperSubstantial claim - Findingreasoning
The difference in the bias applied to the LED pixel can turn it on or off.
“This difference in the bias applied to the LED pixel can turn it on or off.”
Quote in the paperSubstantial claim - Findingreasoning
Random networks of electrospun mNFs can present wide ranges of sheet resistance and transparency (~1.3 ohm/sq with transmittance of 90% or ~0.3 ohm/sq with transmittance of 72% in the visible wavelength regime) by modulating the area fraction of mNFs.
“For example, random networks of these electrospun mNFs can present the wide ranges of superior Rs and transparency (~1.3 ohm/sq with the transmittance of 90% or ~0.3 ohm/sq with the transmittance of 72% in the visible wavelength regime) by modulating the area fraction of mNFs.”
Quote in the paperSubstantial claim - Findingnone given
The rectifier, composed of Si diodes and a capacitor, is integrated with the antenna to convert the ac signal into dc.
“The rectifier, which is composed of Si diodes and a capacitor, is integrated with the antenna to convert the ac signal into dc.”
Quote in the paperSubstantial claim - Findingreasoning
The refractive indices of the silicone elastomer (n = 1.41) and the photocurable optical polymer for the reinforced patterns (n = 1.407) are similarly matched.
“Therefore, the refractive indices of the silicone elastomer (n = 1.41) and the photocurable optical polymer for the reinforced patterns (n = 1.407) are similarly matched.”
Quote in the paperSubstantial claim - Findingnone given
The elastic portion (conventional soft contact lens material) was maximized (more than 96.7%) in the total area of the contact lens for high oxygen permeability (Dk of 340.0 U).
“In addition, the elastic portion (conventional soft contact lens material) was maximized (more than 96.7%) in the total area of the contact lens for high oxygen permeability (Dk of 340.0 U).”
Quote in the paperSubstantial claim - Findingown data
The low haze value of the hybrid was similar to that of a bare elastomer film with no heterogeneous part (~1.3% at 550 nm).
“This low haze value of the hybrid was similar to the case of a bare elastomer film with no heterogeneous part (~1.3% at 550 nm; fig. S3).”
Quote in the paperSubstantial claim - Findingnone given
The main concept of this soft, smart contact lens system is the ability to monitor the status of the wearer's health wirelessly (that is, the glucose level in tears) through the LED pixel.
“The main concept of this soft, smart contact lens system is the ability to monitor the status of the wearer’s health wirelessly (that is, the glucose level in tears) through the LED pixel.”
Quote in the paperSubstantial claim - Findingown data
The rectifier converts the ac signal at 50 MHz into a dc bias of 10 Vrms.
“In addition, the rectifier converts the ac signal at 50 MHz into a dc bias of 10 Vrms (Fig. 3D).”
Quote in the paperSubstantial claim - Findingreasoning
After oxidation, the reduced GOD can be oxidized again by reacting with oxygen molecules, resulting in the formation of hydrogen peroxide as a by-product.
“After the oxidation, the reduced GOD can be oxidized again by reacting with oxygen molecules, which results in the formation of hydrogen peroxide as a by-product.”
Quote in the paperSubstantial claim - Findingreasoning
The antenna inside the elastic region of the smart contact lens had stable performance at 50 MHz with negligible degradation of power reception even after mechanical stretching up to 30% in tensile strain.
“Because of the outstanding stretchability of AgNF networks, the antenna inside the elastic region of the smart contact lens had a stable performance at 50 MHz with negligible degradation of power reception, even after mechanical stretching up to 30% in tensile strain (Fig. 3B).”
Quote in the paperSubstantial claim - Findingown data
The OP-LENS hybrid film (Δn = 0.003) provides a clearer image with lower haze than the SU8-LENS hybrid substrate (Δn = 0.185).
“Figure 2H demonstrates that the OP-LENS hybrid film (Δn = 0.003) provides a clearer image with lower haze than the SU8-LENS hybrid substrate (Δn = 0.185).”
Quote in the paperSubstantial claim - Findingreasoning
When glucose passes through the graphene channel of the sensor, it can be oxidized by GOD.
“When glucose passes through the graphene channel of this sensor, it can be oxidized by GOD.”
Quote in the paperSubstantial claim - Findingown data
The Si diodes in the rectifier had a negligible change in electrical performance even during stretching (30% in tensile strain) due to the hybrid substrate.
“Figure 3C shows that the Si diodes in this rectifier had a negligible change in their electrical performance even during the stretching state (30% in tensile strain) due to the hybrid substrate.”
Quote in the paperSubstantial claim - Findingreasoning
Coimmobilizing catalase (CAT) with glucose oxidase (GOD) on the graphene channel improved the glucose sensor's sensitivity compared with GOD alone.
“The use of CAT improved the sensitivity of the sensor by increasing the enzymatic activity of GOD (Fig. 4A).”
Quote in the paperSubstantial claim - Findingown data
The resulting smart contact lens can receive inductively coupled ac power wirelessly from a transmitting coil at 50 MHz at a distance of 5 mm.
“The resulting smart contact lens can receive inductively coupled ac power wirelessly from a transmitting coil (at 50 MHz) at the distance of 5 mm.”
Quote in the paperSubstantial claim - Findingcitation
Hydrogen peroxide is decomposed, producing oxygen, protons (H+ ion), and electrons.
“This hydrogen peroxide is also decomposed, producing oxygen, protons (H+ ion), and electrons (14, 16, 37).”
Quote in the paperSubstantial claim0 of 3 sources checked- cites [14] Kim J., Kim M., Lee M.-S., Kim K., Ji S., Kim Y.-T., Park J., Na K., Bae K.-H., Kim H. K., Bien F., Lee C. Y., Park J.-U., Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics. Nat. Commun. 8, 14997 (2017). 28447604 PMC5414034 source
Not checked in the free run.
- cites [16] Yao H., Shum A. J., Cowan M., Lähdesmäki I., Parviz B. A., A contact lens with embedded sensor for monitoring tear glucose level. Biosens. Bioelectron. 26, 3290– 3296 (2011). 21257302 PMC3043144 source
Not checked in the free run.
- cites [37] Liu J., Agarwal M., Varahramyan K., Glucose sensor based on organic thin film transistor using glucose oxidase and conducting polymer. Sens. Actuators B Chem. 135, 195– 199 (2008). source
Not checked in the free run.
- Findingreasoning
The protons cause the positive charge transfer effect of the graphene channel (p-type).
“The protons cause the positive charge transfer effect of the graphene channel (p-type).”
Quote in the paperSubstantial claim - Findingown data
The antenna most effectively absorbed RF energy at the frequency of 50 MHz, with a power transfer efficiency of 21.5%.
“Figure S8C presents the power transfer efficiency of this antenna measured at the distance of 5 mm from a transmitting coil, and the antenna most effectively absorbed RF energy at the frequency of 50 MHz, with a power transfer efficiency of 21.5%.”
Quote in the paperNot a substantial claim - Findingown data
The antenna received sufficient voltage (more than 10 V) to turn on LEDs wirelessly at 50 MHz.
“In addition, the antenna received sufficient voltage (more than 10 V) to turn on LEDs wirelessly at 50 MHz (fig. S8D).”
Quote in the paperSubstantial claim - Findingcitation
For selective and sensitive glucose detection, glucose oxidase (GOD; β-d-glucose from Aspergillus niger) was immobilized on the graphene surface with a pyrene linker through the π-π stacking interaction.
“The main mechanism of glucose sensing in this system is that for the selective and sensitive glucose detection, glucose oxidase (GOD; β-d-glucose from Aspergillus niger) was immobilized on the graphene surface with a pyrene linker through the π-π stacking interaction (35, 36).”
Quote in the paperSubstantial claim0 of 2 sources checked- cites [35] Besteman K., Lee J.-O., Wiertz F. G. M., Heering H. A., Dekker C., Enzyme-coated carbon nanotubes as single-molecule biosensors. Nano Lett. 3, 727– 730 (2003). source
Not checked in the free run.
- cites [36] Chen R. J., Zhang Y., Wang D., Dai H., Noncovalent sidewall functionalization of single-walled carbon nanotubes for protein immobilization. J. Am. Chem. Soc. 123, 3838– 3839 (2001). 11457124 source
Not checked in the free run.
- Findingown data
The transmitted ac signal can be rectified through the half-wave rectifying circuit to dc power to turn on the LED pixel.
“Then, the transmitted ac signal can be rectified through the half-wave rectifying circuit to dc power to turn on the LED pixel (Fig. 3F and movie S2).”
Quote in the paperSubstantial claim - Findingown data
The AgNF networks exhibited good mechanical stretchability (with ΔR/R0 less than 10% under a tensile strain of 30%).
“In addition, the AgNF networks exhibited good mechanical stretchability (with ΔR/R0 less than 10% under a tensile strain of 30%), as plotted in fig. S8B.”
Quote in the paperSubstantial claim - Findingown data
AgNF networks with an area fraction of 0.2 had a low sheet resistance of 0.3 ohm/sq (with transmittance of 72%).
“AgNF networks with an area fraction of 0.2 had a low Rs value of 0.3 ohm/sq (with transmittance of 72%).”
Quote in the paperSubstantial claim - Findingown data
After molding to the round shape of the soft contact lens, the integrated electronic system operated reliably during mechanical deformations, including bending and stretching.
“After molding this to the round shape of the soft contact lens, the integrated electronic system operated reliably during mechanical deformations, including bending and stretching.”
Quote in the paperSubstantial claim - Findingown data
After putting the soft lens onto the rabbit's eye, the increase of glucose concentration above the threshold was wirelessly monitored by observing the LED on/off operation.
“After putting this soft lens onto the rabbit’s eye, we were able to wirelessly monitor the increase of the glucose concentration above the threshold by observing the LED on/off operation.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Findingown data
The glucose sensor's response time (time to reach 90% of response) was approximately 1.3 s.
“Therefore, the response time is measured as ~1.3 s, as shown in fig. S12.”
Quote in the paperNot a substantial claim - Findingnone given
For the smart lens, electronic components (glucose sensor, LED pixel, rectifier circuit, and stretchable transparent antenna) were integrated onto a mechanical stress-tunable hybrid substrate with well-matched refractive indices for high optical transparency and low haze.
“For this smart lens, electronic components (that is, the glucose sensor, LED pixel, rectifier circuit, and the stretchable, transparent antenna) were integrated onto the mechanical stress-tunable hybrid substrate with well-matched refractive indices for high optical transparency and low haze.”
Quote in the paperSubstantial claim - Findingown data
For glucose concentrations above 0.9 mM, the LED turned off in the in vivo rabbit test.
“For the glucose concentration of more than 0.9 mM, the LED turned off, as shown in right image of Fig. 5D and movie S3.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Findingown data
The temperature of the smart contact lens device was maintained at ~37°C without significant heat generation during wireless operation while worn by the rabbit.
“Although the rabbit was wearing the wirelessly operating lens circuit, the temperature of this lens device was maintained at ~37°C without any significant generation of heat.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Findingreasoning
The smart contact lens showed nearly constant output voltages through the antenna-rectifier even after 48 hours.
“In addition, this lens also showed nearly constant output voltages through the antenna-rectifier even after 48 hours”
Quote in the paperSubstantial claim - Findingown data
The glucose sensor can detect the wide range of tear glucose concentrations from 0.2 to 0.6 mM and above 0.9 mM.
“and this sensor can detect these wide ranges (Fig. 4B).”
Quote in the paperSubstantial claim - Findingown data
A fully functional smart contact lens was fabricated by integrating the glucose sensor with the wireless display (LED pixel, rectifying circuit, and antenna) using the hybrid substrate.
“This glucose sensor was integrated with the wireless display (the LED pixel, rectifying circuit, and antenna) using the hybrid substrate as a fully functional smart contact lens.”
Quote in the paperSubstantial claim - Findingown data
The minimum detectable glucose concentration of the sensor, for an SNR of ~3, was approximately 12.57 μM.
“and the minimum detectable concentration (for the case of an SNR of ~3) was approximately estimated to be about 12.57 μM.”
Quote in the paperSubstantial claim - Findingown data
The smart contact lens showed negligible degradation of response after storage in artificial tear solution for up to 48 hours.
“There is negligible degradation of the response even after 48 hours”
Quote in the paperSubstantial claim- Rests on an assumption: Artificial tear solution is a valid proxy for human tears for testing the smart contact lens.
- Findingown data
The glucose sensor on a bare elastomeric film without the hybrid substrate did not have negligible change in resistance under tensile strain up to 30%.
“unlike the glucose sensor on a bare elastomeric film (with no use of the hybrid substrate).”
Quote in the paperSubstantial claim - Findingown data
According to simulation results for specific absorption rate (SAR) for a person, the maximum SAR value of the smart contact lens system was 1.399 W/kg, which is much lower than the regulation value of 10 W/kg.
“the maximum SAR value of our smart contact lens system was 1.399 W/kg (fig. S15), which is much lower than the regulation value (10 W/kg) (42).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [42] IEEE, IEEE standard for safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 kHz to 300 GHz, in IEEE Std C951-2005 (Revision of IEEE Std C951-1991) (IEEE, 2006), 238 pp.
Not checked in the free run.
- Findingown data
The relative change in resistance (ΔR/R0) of the glucose sensor decreased linearly with glucose concentration.
“The relative change in resistance (ΔR/R0) of this sensor decreased linearly with the glucose concentration, as shown in the inset of Fig. 4B.”
Quote in the paperSubstantial claim - Findingown data
The glucose sensor integrated on a soft contact lens with the hybrid substrate had a negligible change in resistance for tensile strain up to 30%.
“Figure 4D shows that the glucose sensor with the hybrid substrate has a negligible change in its resistance for a tensile strain of up to 30%”
Quote in the paperSubstantial claim - Findingown data
The glucose sensor's sensitivity, defined as the slope of the calibration curve, was approximately −22.72%/mM.
“so the sensitivity is calculated as approximately −22.72%/mM.”
Quote in the paperSubstantial claim - Findingown data
The measured signal-to-noise ratio (SNR) of the glucose sensor at 0.1 mM glucose was 23.87.
“The measured signal-to-noise ratio (SNR) at 0.1 mM was 23.87”
Quote in the paperNot a substantial claim - Findingown data
The glucose sensor's response (ΔR/R0) did not differ significantly between buffered solution and artificial tear solution after adding glucose.
“The deviation from the sensor response (ΔR/R0) was not significant for the cases of buffered or tear solutions, as shown in Fig. 4C”
Quote in the paperSubstantial claim- Rests on an assumption: Human tears contain various species besides glucose.
- Findingown data
After 5000 cycles of stretching and releasing at 30% tensile strain, the smart contact lens operated stably with negligible degradation.
“After 5000 cycles of stretching and releasing with the tensile strain of 30%, the smart contact lens operated stably with negligible degradation (fig. S13C).”
Quote in the paperSubstantial claim - Premisecitation
The user's tears can be collected in a contact lens by natural means such as normal secretion and blinking and used to assess biomarkers found in the blood, such as glucose, cholesterol, sodium ions, and potassium ions.
“In addition, the user’s tears can be collected in the contact lens by completely natural means, such as normal secretion and blinking, and used to assess various biomarkers found in the blood, such as glucose, cholesterol, sodium ions, and potassium ions (13).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [13] Farandos N. M., Yetisen A. K., Monteiro M. J., Lowe C. R., Yun S. H., Contact lens sensors in ocular diagnostics. Adv. Healthc. Mater. 4, 792– 810 (2015). 25400274 source
Not checked in the free run.
- Interpretationreasoning
Lens equipped with sensors can provide noninvasive methods to continuously detect metabolites in tears.
“Thus, lens equipped with sensors can provide noninvasive methods to continuously detect metabolites in tears.”
Quote in the paperSubstantial claim - Premisecitation
Brittle and rigid materials of the integrated electronic system, such as surface-mounted IC chips and rigid interconnects, could damage the cornea or the eyelid.
“(iii) the brittle and rigid materials of the integrated electronic system, such as surface-mounted IC chips and rigid interconnects, which could damage the cornea or the eyelid (20–22);”
Quote in the paperSubstantial claim0 of 3 sources checked- cites [20] Liao Y.-T., Yao H., Lingley A., Parviz B., Otis B. P., A 3-μW CMOS glucose sensor for wireless contact-lens tear glucose monitoring. IEEE J. Solid-State Circuits 47, 335– 344 (2012). source
Not checked in the free run.
- cites [21] Piso D., Veiga-Crespo P., Vecino E., Modern monitoring intraocular pressure sensing devices based on application specific integrated circuits. J. Biomater. Nanobiotechnol. 3, 301– 309 (2012). source
Not checked in the free run.
- cites [22] Pandey J., Liao Y.-T., Lingley A., Mirjalili R., Parviz B., Otis B. P., A fully integrated RF-powered contact lens with a single element display. IEEE Trans. Biomed. Circuits Syst. 4, 454– 461 (2010). 23853383 source
Not checked in the free run.
- Premisecitation
The requirement for bulky and expensive equipment for signal measurements limits the use of smart contact lenses outside research laboratories or clinical settings by restricting users' external activities.
“(iv) the requirement for bulky and expensive equipment for signal measurements, which limits the use of smart contact lenses outside of research laboratories or clinical settings by restricting users’ external activities (14, 15, 20, 23).”
Quote in the paperSubstantial claim0 of 4 sources checked- cites [14] Kim J., Kim M., Lee M.-S., Kim K., Ji S., Kim Y.-T., Park J., Na K., Bae K.-H., Kim H. K., Bien F., Lee C. Y., Park J.-U., Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics. Nat. Commun. 8, 14997 (2017). 28447604 PMC5414034 source
Not checked in the free run.
- cites [15] Chu M. X., Miyajima K., Takahashi D., Arakawa T., Sano K., Sawada S.-i., Kudo H., Iwasaki Y., Akiyoshi K., Mochizuki M., Mitsubayashi K., Soft contact lens biosensor for in situ monitoring of tear glucose as non-invasive blood sugar assessment. Talanta 83, 960– 965 (2011). 21147344 source
Not checked in the free run.
- cites [20] Liao Y.-T., Yao H., Lingley A., Parviz B., Otis B. P., A 3-μW CMOS glucose sensor for wireless contact-lens tear glucose monitoring. IEEE J. Solid-State Circuits 47, 335– 344 (2012). source
Not checked in the free run.
- cites [23] Leonardi M., Leuenberger P., Bertrand D., Bertsch A., Renaud P., First steps toward noninvasive intraocular pressure monitoring with a sensing contact lens. Invest. Ophthalmol. Vis. Sci. 45, 3113– 3117 (2004). 15326128 source
Not checked in the free run.
- Premisecitation
Opaque electronic materials for sensors, IC chips, metal antennas, and interconnects can block users' vision.
“These issues include (i) the use of opaque electronic materials for sensors, integrated circuit (IC) chips, metal antennas, and interconnects that can block users’ vision (15, 17, 18);”
Quote in the paperSubstantial claim0 of 3 sources checked- cites [15] Chu M. X., Miyajima K., Takahashi D., Arakawa T., Sano K., Sawada S.-i., Kudo H., Iwasaki Y., Akiyoshi K., Mochizuki M., Mitsubayashi K., Soft contact lens biosensor for in situ monitoring of tear glucose as non-invasive blood sugar assessment. Talanta 83, 960– 965 (2011). 21147344 source
Not checked in the free run.
- cites [17] Lingley A. R., Ali M., Liao Y., Mirjalili R., Klonner M., Sopanen M., Suihkonen S., Shen T., Otis B. P., Lipsanen H., Parviz B. A., A single-pixel wireless contact lens display. J. Micromech. Microeng. 21, 125014 (2011). source
Not checked in the free run.
- cites [18] Chen G.-Z., Chan I.-S., Lam D. C. C., Capacitive contact lens sensor for continuous non-invasive intraocular pressure monitoring. Sens. Actuators A Phys. 203, 112– 118 (2013). source
Not checked in the free run.
- Premisecitation
Integration of electronic device components on flat and plastic substrates results in buckled deformations when transformed into the curved shape for lenses, creating foreign objects that can irritate users' eyes and eyelids.
“(ii) the integration of the components of the electronic device on flat and plastic substrates, resulting in buckled deformations when transformed into the curved shape for lenses, thereby creating foreign objects that can irritate users’ eyes and eyelids (19);”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [19] De Smedt S., Noninvasive intraocular pressure monitoring: Current insights. Clin. Ophthalmol. 9, 1385– 1392 (2015). 26257509 PMC4525787 source
Not checked in the free run.
- Interpretationreasoning
The in-plane stretchability of mNF electrodes can prevent mechanical buckling of devices on a soft lens to delay irritation of the eye or eyelid caused by feeling the presence of foreign objects.
“In particular, their in-plane stretchability can prevent mechanical buckling of devices on a soft lens to delay the irritation of the eye or eyelid caused by feeling the presence of foreign objects.”
Quote in the paperSubstantial claim - Interpretationown data
The hybrid substrate can protect ordinary electronics from mechanical fractures.
“This result proves that the hybrid substrate can protect ordinary electronics from mechanical fractures.”
Quote in the paperSubstantial claim - Interpretationown data
The hybrid substrate with well-matched refractive indices can prevent interference with the wearer's field of view.
“This result means that the hybrid substrate with the well-matched refractive indices can prevent interference with the wearer’s field of view.”
Quote in the paperSubstantial claim - Interpretationreasoning
The single-loop antenna of the smart lens, located outside the pupil of a person's eye, prevents interference with the wearer's field of view.
“This single-loop antenna of the smart lens, which can be located outside the pupil of a person’s eye (diameter of pupil, ~6 mm), prevents interference with the wearer’s field of view.”
Quote in the paperSubstantial claim - Interpretationown data
Because the elastic area of the smart contact lens absorbs most of the applied strain, the integrated devices can operate reliably in the form of a soft contact lens.
“Because the elastic area of the smart contact lens absorbs most of the applied strain, the integrated devices can operate reliably in the form of a soft contact lens.”
Quote in the paperSubstantial claim - Interpretationown data
The AgNF sample showed superior mechanical durability as an antenna structure on curvilinear surfaces such as contact lenses.
“Thus, this sample showed superior mechanical durability as a form of the antennas structure on curvilinear surfaces such as contact lenses.”
Quote in the paperSubstantial claim - Interpretationcitation
Because the major carrier density is proportional to the glucose concentration, the relative change in resistance (ΔR/R0) of the sensor can be detected as a function of the glucose concentration.
“Because the major carrier density is proportional to the glucose concentration, we can detect the relative change in resistance (ΔR/R0) of the sensor as a function of the glucose concentration generated from the above reaction processes (14, 38).”
Quote in the paperSubstantial claim0 of 2 sources checked- cites [14] Kim J., Kim M., Lee M.-S., Kim K., Ji S., Kim Y.-T., Park J., Na K., Bae K.-H., Kim H. K., Bien F., Lee C. Y., Park J.-U., Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics. Nat. Commun. 8, 14997 (2017). 28447604 PMC5414034 source
Not checked in the free run.
- cites [38] Ngoepe M., Choonara Y. E., Tyagi C., Tomar L. K., du Toit L. C., Kumar P., Ndesendo V. M. K., Pillay V., Integration of biosensors and drug delivery technologies for early detection and chronic management of illness. Sensors 13, 7680– 7713 (2013). 23771157 PMC3715220 source
Not checked in the free run.
- Interpretationreasoning
The improvement in sensitivity from CAT was due to CAT increasing the enzymatic activity of GOD.
“The use of CAT improved the sensitivity of the sensor by increasing the enzymatic activity of GOD (Fig. 4A).”
Quote in the paperSubstantial claim - Interpretationreasoning
The nearly constant output voltages after 48 hours are due to passivation by the hybrid substrate and parylene, which act as a diffusional barrier.
“because they are passivated by the hybrid substrate and parylene, which can act as a diffusional barrier (fig. S13B).”
Quote in the paperSubstantial claim - Interpretationreasoning
When the glucose concentration is above 0.9 mM, the LED pixel turns off because the bias applied to the LED becomes below its turn-off voltage.
“When the glucose concentration is above 0.9 mM, this pixel turns off because the bias applied to the LED becomes below than its turn-off voltage.”
Quote in the paperSubstantial claim - Interpretationown data
Other species in human tears besides glucose had negligible interference with the glucose sensor.
“which indicates that other species in tears (besides glucose) had a negligible interference with this glucose sensor.”
Quote in the paperSubstantial claim- Rests on an assumption: Human tears contain various species besides glucose.
- Study design and conductown data
The stable status of the smart contact lens was proven by operations with higher power transfer.
“The stable status of the smart contact lens was proven by the operations with higher power transfer (movie S3).”
Quote in the paperNot a substantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Interpretationown data
The authors developed a method to fabricate a soft, smart contact lens that can monitor glucose levels in tears to indicate the diabetic condition in real time through a display with wireless operations.
“In conclusion, we developed a method to fabricate a soft, smart contact lens that can monitor glucose levels in tears to indicate the diabetic condition in real time through a display with wireless operations.”
Quote in the paperSubstantial claim- Rests on an assumption: Artificial tear solution is a valid proxy for human tears for testing the smart contact lens.
- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Interpretationreasoning
As glucose concentration increases, the bias applied to the LED pixel and the luminance of the LED decrease until the threshold.
“Therefore, the bias applied to the LED pixel and the luminance of the LED decrease as the glucose concentration increases until the threshold (fig. S14).”
Quote in the paperSubstantial claim - Interpretationreasoning
The rapid molding approach, together with conventional processing steps, can represent potential for large-scale mass production.
“This rapid molding approach, together with conventional processing steps (for example, photolithography and metallization by evaporation), can represent its potential for large-scale mass production.”
Quote in the paperNot a substantial claim - Interpretationown data
The enzymes in the smart contact lens maintain their activity for at least 48 hours.
“which suggests that the enzymes maintain their activity for at least 48 hours (fig. S13A).”
Quote in the paperSubstantial claim- Rests on an assumption: Artificial tear solution is a valid proxy for human tears for testing the smart contact lens.
- Interpretationown data
Placing the glucose sensor on the reinforced part of the hybrid substrate prevents it from being damaged by mechanical deformations of the soft contact lens.
“Despite the use of the soft lens, the location of this sensor on the reinforced part of the hybrid substrate prevents it from being damaged by mechanical deformations of the soft contact lens.”
Quote in the paperSubstantial claim - Interpretationown data
The in vivo tests using a live rabbit, including monitoring temperature change on the rabbit's eye, provided substantial promise of future smart contact lenses for noninvasive health care monitoring using human eyes and tears.
“The in vivo tests using a live rabbit, including the monitoring of the temperature change on the rabbit’s eye, provided the substantial promise of future smart contact lenses for noninvasive health care monitoring using human eyes and tears.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
- Classified as probably not a substantial claim. 7
- May combine two claims. 21
Probably not a substantial claim: may not pass S4 (based).
Findingnone givenDisplay pixels integrated in the smart contact lens allow access to real-time sensing data to eliminate the need for additional measurement equipment.
“In addition, display pixels integrated in the smart contact lens allow access to real-time sensing data to eliminate the need for additional measurement equipment.”
Quote in the paperNot a substantial claimMay combine two claims.
FindingreasoningCharge transport occurs along the 1D metallic pathways, and their ultralong length facilitates reduction of sheet resistance by minimizing the number of junctions between the metal fibers.
“Charge transport occurs along these 1D metallic pathways, and their ultralong length facilitates the reduction of sheet resistance (Rs) by minimizing the number of junctions between the metal fibers.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S4 (based). May combine two claims.
Findingnone givenWireless operations of this smart contact lens can maintain the eye temperature stably without abrupt heating, ensuring the safety of the wearer's eyes.
“In addition, wireless operations of this smart contact lens can maintain the eye temperature stably without abrupt heating, ensuring the safety of the wearer’s eyes.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe hybrid substrate exhibited superb optical transmittance (~93% at 550 nm) and low haze (~1.6% at 550 nm).
“Figure 2F shows that this hybrid substrate exhibited superb optical transmittance (~93% at 550 nm) and low haze (~1.6% at 550 nm).”
Quote in the paperSubstantial claimMay combine two claims.
FindingcitationAlthough the hybrid film was stretched up to 30% in tensile strain, negligible strain (~0%) was applied on the reinforced islands, and the elastic region was mainly stretched because of the significant difference in Young's modulus.
“Although this hybrid film was stretched up to 30% in tensile strain, negligible strain (~0%) was applied on the reinforced islands, and the elastic region was mainly stretched because of the significant difference in Young’s modulus (24, 27, 28).”
Quote in the paperSubstantial claim0 of 3 sources checked- cites [24] Graz I. M., Cotton D. P. J., Robinson A., Lacour S. P., Silicone substrate with in situ strain relief for stretchable thin-film transistors. Appl. Phys. Lett. 98, 124101 (2011). source
Not checked in the free run.
- cites [27] Romeo A., Liu Q., Suo Z., Lacour S. P., Elastomeric substrates with embedded stiff platforms for stretchable electronics. Appl. Phys. Lett. 102, 131904 (2013). source
Not checked in the free run.
- cites [28] Ji S., Hyun B. G., Kim K., Lee S. Y., Kim S.-H., Kim J.-Y., Song M. H., Park J.-U., Photo-patternable and transparent films using cellulose nanofibers for stretchable origami electronics. NPG Asia Mater. 8, e299 (2016). source
Not checked in the free run.
Probably not a substantial claim: may not pass S4 (based).
Findingnone givenIn this wireless circuit system, tear fluids with glucose concentration above the threshold will turn off the LED pixel.
“For example, in this wireless circuit system, tear fluids with glucose concentration above the threshold will turn off the LED pixel.”
Quote in the paperNot a substantial claimMay combine two claims.
FindingreasoningThe index-matching approach provides the wearer with outstanding transparency (93% in the visible light regime) and low haze (1.6% in the visible light regime).
“This index-matching approach can provide the wearer with a clear view, that is, outstanding transparency (93% in the visible light regime) and low haze (1.6% in the visible light regime).”
Quote in the paperSubstantial claimMay combine two claims.
FindingreasoningThe rectified dc power turns on the LED pixel and glucose sensor.
“The rectified dc power turns on the LED pixel and glucose sensor.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataThe root-mean-square surface roughness of the entire regime and the height difference at the interface were less than 3 and 5 nm, respectively.
“The root-mean-square (rms) surface roughness of the entire regime and the height difference at this interface were measured and found to be less than 3 and 5 nm, respectively.”
Quote in the paperSubstantial claimMay combine two claims.
FindingreasoningThe reduction in sensor resistance decreases the resistance of the parallel circuit of the LED and sensor, whereas the resistance of other components (antenna and rectifier) in the system is constant.
“This reduction in the sensor resistance decreases the resistance of the parallel circuit of the LED and sensor, whereas the resistance of other components (antenna and rectifier) in the system is constant.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataThe wireless display was integrated with a glucose sensor to produce a soft, smart contact lens that can respond to changes in glucose level and simultaneously display the sensing information through the LED pixel.
“The wireless display was subsequently integrated with a glucose sensor to produce a soft, smart contact lens that can respond to the changes in glucose level and simultaneously display the sensing information through the LED pixel (Fig. 1C).”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataWireless power transfer from the transmitting coil to the lens increased the temperature of the transmitting coil to ~42°C, but the coil did not touch the rabbit's eye or eyelid due to a gap of ~5 mm.
“Although the wireless power transfer from the transmitting coil to the lens increased the temperature of this transmitting coil to ~42°C, which was slightly higher than the temperature of the surroundings, its wireless function prevented this coil from touching the rabbit’s eye or eyelid with a gap of ~5 mm.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
May combine two claims.
Findingown dataThe rabbit showed no signs of abnormal behavior, and the smart lens remained stable during repeated eye blinks.
“The rabbit showed no signs of abnormal behavior, and this smart lens remained stable during repeated eye blinks.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
Probably not a substantial claim: may not pass S2 (checkable).
PremisecitationA smart contact lens is a promising wearable health monitoring device.
“Given this background, a smart contact lens is a promising example of a wearable, health monitoring device (13, 14).”
Quote in the paperNot a substantial claim0 of 2 sources checked- cites [13] Farandos N. M., Yetisen A. K., Monteiro M. J., Lowe C. R., Yun S. H., Contact lens sensors in ocular diagnostics. Adv. Healthc. Mater. 4, 792– 810 (2015). 25400274 source
Not checked in the free run.
- cites [14] Kim J., Kim M., Lee M.-S., Kim K., Ji S., Kim Y.-T., Park J., Na K., Bae K.-H., Kim H. K., Bien F., Lee C. Y., Park J.-U., Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics. Nat. Commun. 8, 14997 (2017). 28447604 PMC5414034 source
Not checked in the free run.
Probably not a substantial claim: may not pass S4 (based).
Interpretationnone givenThe wearer's view will not be obstructed because the contact lenses are made of transparent nanomaterials.
“For example, the wearer’s view will not be obstructed because the contact lenses are made of transparent nanomaterials.”
Quote in the paperNot a substantial claimMay combine two claims.
PremisecitationBy considering the correlation between tear glucose level and blood glucose level, a glucose sensor fitted on a contact lens can provide noninvasive monitoring of a user's glucose levels from tear fluids, with a lag time between tear glucose and blood glucose in the range of 10 to 20 min.
“By considering the correlation between the tear glucose level and blood glucose level (15), a glucose sensor fitted on a contact lens can provide the noninvasive monitoring of user’s glucose levels from tear fluids with a consideration of the lag time between tear glucose level and blood glucose level in the range of 10 to 20 min (13–16).”
Quote in the paperSubstantial claim0 of 4 sources checked- cites [15] Chu M. X., Miyajima K., Takahashi D., Arakawa T., Sano K., Sawada S.-i., Kudo H., Iwasaki Y., Akiyoshi K., Mochizuki M., Mitsubayashi K., Soft contact lens biosensor for in situ monitoring of tear glucose as non-invasive blood sugar assessment. Talanta 83, 960– 965 (2011). 21147344 source
Not checked in the free run.
- cites [13] Farandos N. M., Yetisen A. K., Monteiro M. J., Lowe C. R., Yun S. H., Contact lens sensors in ocular diagnostics. Adv. Healthc. Mater. 4, 792– 810 (2015). 25400274 source
Not checked in the free run.
- cites [14] Kim J., Kim M., Lee M.-S., Kim K., Ji S., Kim Y.-T., Park J., Na K., Bae K.-H., Kim H. K., Bien F., Lee C. Y., Park J.-U., Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics. Nat. Commun. 8, 14997 (2017). 28447604 PMC5414034 source
Not checked in the free run.
- cites [16] Yao H., Shum A. J., Cowan M., Lähdesmäki I., Parviz B. A., A contact lens with embedded sensor for monitoring tear glucose level. Biosens. Bioelectron. 26, 3290– 3296 (2011). 21257302 PMC3043144 source
Not checked in the free run.
May combine two claims.
InterpretationreasoningThis soft, smart contact lens provides a platform for wireless, continuous, and noninvasive monitoring of physiological conditions, as well as the detection of biomarkers associated with ocular and other diseases.
“Therefore, this soft, smart contact lens provides a platform for wireless, continuous, and noninvasive monitoring of physiological conditions, as well as the detection of biomarkers associated with ocular and other diseases.”
Quote in the paperSubstantial claim- Rests on an assumption: The live rabbit is a representative model for the human eye for safety and reliable operation of the smart contact lens.
- Rests on an assumption: The glucose threshold for LED switching corresponds to a clinically relevant glucose level for screening prediabetes and monitoring glucose daily.
May combine two claims.
Interpretationown dataThe nearly flat interface is advantageous in reducing light scattering from the interfacial surface and is in close contact with masks for photolithography.
“This nearly flat interface is advantageous in reducing light scattering from the interfacial surface, and it is in close contact with masks for photolithography.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataThe hybrid substrate system can offer sufficient stretchability over the entire region, whereas brittle inorganic devices located on the reinforced islands can be protected from mechanical deformations.
“Hence, these results indicate that our hybrid substrate system can offer sufficient stretchability over the entire region, whereas the brittle inorganic devices (LED, Si diode, and capacitor for the rectifier), which are located on the reinforced islands, can be protected from the mechanical deformations.”
Quote in the paperSubstantial claimMay combine two claims.
InterpretationreasoningThis is the first approach to apply a display pixel into a soft contact lens to visualize glucose sensing, which can be used to screen for prediabetes and monitor the glucose level daily without additional bulky and expensive measurement equipment.
“It is the first approach to apply the display pixel into a soft contact lens to visualize glucose sensing, which can be used to screen for prediabetes and monitor the glucose level daily, without the requirement of additional, bulky, and expensive measurement equipment.”
Quote in the paperNot a substantial claim- Rests on an assumption: The glucose threshold for LED switching corresponds to a clinically relevant glucose level for screening prediabetes and monitoring glucose daily.
May combine two claims.
PremisecitationThe average glucose level in tears is 0.2-0.6 mM for normal people and can exceed 0.9 mM for people with diabetes.
“The average glucose levels of tears for normal people are in the range of 0.2 to 0.6 mM, but this average can exceed 0.9 mM for people with diabetes (40)”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [40] Sen D. K., Sarin G. S., Tear glucose levels in normal people and in diabetic patients. Br. J. Ophthalmol. 64, 693– 695 (1980). 7426593 PMC1043796 source
Not checked in the free run.
May combine two claims.
InterpretationreasoningThe LED pixel turned off because the glucose concentration was over the threshold, not because of damage to the circuit.
“Hence, the LED pixel turned off because the glucose concentration was over the threshold, not because of damage to the circuit.”
Quote in the paperSubstantial claim- Rests on an assumption: The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
May combine two claims.
PremisecitationThe average glucose level of tears for fasting diabetic patients typically exceeds 0.9 mM, and for fasting people without diabetes it is below 0.6 mM.
“Because the average glucose level of tears for fasting diabetic patients typically exceeds 0.9 mM and the concentration for fasting people without diabetes is below 0.6 mM (39)”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [39] Singh S., McShane M., Enhancing the longevity of microparticle-based glucose sensors towards 1 month continuous operation. Biosens. Bioelectron. 25, 1075– 1081 (2010). 19926464 PMC2818267 source
Not checked in the free run.
May combine two claims.
InterpretationcitationThe parylene passivation layer on the AgNF-based electrodes and devices in the smart contact lens acts as a diffusional barrier that prevents leakage of AgNFs and protects the AgNFs from tear fluid.
“The AgNF-based electrodes and devices in the resulting smart contact lens are passivated by the parylene layer such that this passivation layer of parylene, as a diffusional barrier, prevents the leakage of AgNFs and simultaneously ensures the protection of the AgNFs from tear fluid (41).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [41] Rodger D. C., Weiland J. D., Humayun M. S., Tai Y.-C., Scalable high lead-count parylene package for retinal prostheses. Sens. Actuators B Chem. 117, 107– 114 (2006). source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductnone givenAll in vivo studies were conducted according to the guidelines of the National Institutes of Health for care and use of laboratory animals and with approval of the Institute of Animal Care and Use Committee of UNIST (UNISTIACUC-16-19).
“All in vivo studies were conducted according to the guidelines of the National Institutes of Health for care and use of laboratory animals and with the approval of the Institute of Animal Care and Use Committee of the Ulsan National Institute of Science and Technology (UNIST) (UNISTIACUC-16-19).”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing), S4 (based).
Interpretationnone givenThe threshold can be tuned simply by changing the resistance of the sensor.
“This threshold can be tuned simply by changing the resistance of the sensor.”
Quote in the paperNot a substantial claim
The paper relies on this without support.
The live rabbit is a representative model for the human eye for safety and reliable operation of the smart contact lens.
“Furthermore, in vivo tests using a live rabbit demonstrated its reliable operation without noticeable adverse effects.”
The paper relies on this without support.
The glucose threshold for LED switching corresponds to a clinically relevant glucose level for screening prediabetes and monitoring glucose daily.
“For example, in this wireless circuit system, tear fluids with glucose concentration above the threshold will turn off the LED pixel.”
“It is the first approach to apply the display pixel into a soft contact lens to visualize glucose sensing, which can be used to screen for prediabetes and monitor the glucose level daily, without the requirement of additional, bulky, and expensive measurement equipment.”
The paper relies on this without support.
Continuous formation of H2O2 degrades the enzymatic activity of GOD, lowering the sensitivity of the glucose sensor.
“However, the continuous formation of H2O2 can degrade the enzymatic activity of GOD, lowering the sensitivity of this glucose sensor.”
The paper relies on this without support.
Human tears contain various species besides glucose.
“Because human tears contain various species besides glucose, the selectivity of this sensor to glucose was tested using (i) a buffered solution and (ii) a solution of artificial tears.”
The paper relies on this without support.
Artificial tear solution is a valid proxy for human tears for testing the smart contact lens.
“storing in an artificial tear solution for up to 48 hours”
The paper relies on this without support.
The rabbit eye is a valid model for the human eye for in vivo testing of the smart contact lens.
“Figure 5D shows a live rabbit wearing this smart contact lens for an in vivo test.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The work was further expanded for integration of wireless power transfer circuits and displays on contact lens biosensors, visualizing the in vivo rabbit tear glucose response in real-time.
“The work was further expanded for integration of wireless power transfer circuits and displays on contact lens biosensors, visualizing the in vivo rabbit tear glucose response in real-time (Fig. 5c)118.”
From Wearable biosensors for healthcare monitoring (2019) · cites this paper as [118]
The advanced contact lens device focused on ensuring wearer comfort without hindrance to vision through transparent soft materials, while integrating wireless electronics to eliminate the need for an external power source.
“This advanced device focused on ensuring wearer comfort without hindrance to vision through the use of transparent soft materials, while integrating wireless electronics to eliminate the need for an external power source.”
From Wearable biosensors for healthcare monitoring (2019) · cites this paper as [118]
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Self-citationCapacitive contact lens sensor for continuous non-invasive intraocular pressure monitoring
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Self-citationScalable high lead-count parylene package for retinal prostheses
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Self-citationLocally Reinforced Polymer-Based Composites for Elastic Electronics
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Flagged first, then by citations
Research works printed but not linked: 1
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Cited by
Sorted by citations
Wearable biosensors for healthcare monitoring
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Self-citationBio-Integrated Wearable Systems: A Comprehensive Review
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Wearables and the Medical Revolution
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Flexible Hybrid Electronics for Digital Healthcare
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Wireless smart contact lens for diabetic diagnosis and therapy
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Self-citationNon-Invasive Blood Glucose Monitoring Technology: A Review
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Wearable Electrochemical Glucose Sensors in Diabetes Management: A Comprehensive Review
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Self-citationFlexible Plasmonic Biosensors for Healthcare Monitoring: Progress and Prospects
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Recent Advances in Intelligent Wearable Medical Devices Integrating Biosensing and Drug Delivery
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Recent patient health monitoring platforms incorporating internet of things-enabled smart devices
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Flexible Electrochemical Biosensors for Health Monitoring
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Self-citation
- Authors
- Park, J., Kim, J., Kim, S.-Y., Cheong, W. H., Jang, J., Park, Y.-G., Na, K., Kim, Y.-T., Heo, J. H., Lee, C. Y., Lee, J. H., Bien, F., & Park, J.-U.
- Affiliations
- Ulsan National Institute of Science and Technology (KR)
- Sungkyunkwan University (KR)
- Corresponding author
- Park, Jihun
- Kim, Joohee
- Kim, So-Yun
- Lee, Jung Heon
- Bien, Franklin
- Park, Jang-Ung
- ORCID
- Venue
- Science Advances
- Published
- 2018-01-05
- Volume
- 4
- Issue
- 1
- Pages
- eaap9841-eaap9841
- ISSN
- 2375-2548 (ISSN-L)
- PMC
- PMC5787380
- OpenAlex
- W2785523439
- Cited by
- 671
- References
- 45
- Citations by year
- 2026: 58 · 2025: 68 · 2024: 73 · 2023: 68 · 2022: 99 · 2021: 118 · 2020: 83 · 2019: 77 · 2018: 27
- FWCI
- 30.48
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- cc-by-nc
- Locations
- Science Advances (publishedVersion, cc-by-nc)
- PubMed Central (publishedVersion, cc-by-nc)
- PubMed (publishedVersion)
- Scholarworks@UNIST (Ulsan National Institute of Science and Technology) (submittedVersion, cc-by-nc)
- Funders
- National Research Foundation (award366518, 2016R1A2B3013592, award366519, 2016R1A5A1009926)
- Pioneer Research Center Program (award366527, NRF-2014M3C1A3001208)
- Nano Material Technology Development Program (award366520, 2015M3A7B4050308, award366522, 2016M3A7B4910635)
- Convergence Technology Development Program for Bionic Arm (award366524, NRF-2017M3C1B2085316)
- Industrial Technology Innovation Program (award366525, 10080577)
- UNIST (award366528, 1.170009.01)
- Topics
- Physical Sciences › Engineering › Biomedical Engineering › Advanced Sensor and Energy Harvesting Materials
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Nanomaterials and Printing Technologies
- Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
- Keywords
- smart contact lenses, glucose sensor, wireless power transfer, stretchable displays, transparent electronics, diabetes monitoring, wearable electronics, real-time health monitoring, refractive index matching, in vivo evaluation
- MeSH terms
- Contact Lenses, Glucose, Humans, Biosensing Techniques, Wireless Technology
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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
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