Research ArticleAPPLIED SCIENCES AND ENGINEERING

Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays

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Science Advances  24 Jan 2018:
Vol. 4, no. 1, eaap9841
DOI: 10.1126/sciadv.aap9841
  • Fig. 1 Stretchable, transparent smart contact lens system.

    (A) Schematic illustration of the soft, smart contact lens. The soft, smart contact lens is composed of a hybrid substrate, functional devices (rectifier, LED, and glucose sensor), and a transparent, stretchable conductor (for antenna and interconnects). (B) Circuit diagram of the smart contact lens system. (C) Operation of this soft, smart contact lens. Electric power is wirelessly transmitted to the lens through the antenna. This power activates the LED pixel and the glucose sensor. After detecting the glucose level in tear fluid above the threshold, this pixel turns off.

  • Fig. 2 Properties of a stretchable and transparent hybrid substrate.

    (A) Schematic image of the hybrid substrate where the reinforced islands are embedded in the elastic substrate. (B) SEM images before (top) and during (bottom) 30% stretching. The arrow indicates the direction of stretching direction. Scale bars, 500 μm. (C) Effective strains on each part along the stretching direction indicated in (B). (D) AFM image of the hybrid substrate. Black and blue arrows indicate the elastic region and the reinforced island, respectively. Scale bar, 5 μm. (E) Photograph of the hybrid substrates molded into contact lens shape. Scale bar, 1 cm. (F) Optical transmittance (black) and haze (red) spectra of the hybrid substrate. (G) Schematic diagram of the photographing method to identify the optical clarity of hybrid substrates. (H) Photographs taken by camera where the OP-LENS–based hybrid substrate (left) and the SU8-LENS–based hybrid substrate (right) are located on the camera lens.

  • Fig. 3 Wireless display circuit on the hybrid substrate.

    (A) Schematic image of the wireless display circuit. The rectifier and LED are in the reinforced regions. The transparent, stretchable AgNF-based antenna and interconnects are in an elastic region. (B) Relative change in transmitted voltage by antenna as a function of applied strain. (C) Characteristics of Si diode on the hybrid substrate by applying 0 and 30% in tensile strain. (D) Rectified properties of the fabricated rectifier. (E) Photograph of wireless display on the hybrid substrate. Scale bar, 1 cm. (F) Photographs (left, off-state; right, on-state) of operating wireless display with lens shape located on the artificial eye. Scale bars, 1 cm.

  • Fig. 4 Characterization of the glucose sensor.

    (A) Difference in response between glucose concentrations of 0.1 and 0.9 mM for the sensor with GOD functionalization (black) and GOD-CAT functionalization (red). (B) Real-time continuous monitoring according to the glucose concentrations (inset, calibration curves of the glucose sensor). (C) Electrical response for the sensors with different solutions (red, buffered solution; blue, solution of artificial tear). Each data point indicates the average for 10 samples, and error bars represent the SD. (D) Relative changes in the resistance of glucose sensor as a function of tensile strain (red, sensor on the hybrid substrate; black, sensor on the elastomeric film with no use of the hybrid substrate).

  • Fig. 5 Soft, smart contact lens for detecting glucose.

    (A) Schematic image of the soft, smart contact lens. The rectifier, the LED, and the glucose sensor are located on the reinforced regions. The transparent, stretchable AgNF-based antenna and interconnects are located on an elastic region. (B) Photograph of the fabricated soft, smart contact lens. Scale bar, 1 cm. (C) Photograph of the smart contact lens on an eye of a mannequin. Scale bar, 1 cm. (D) Photographs of the in vivo test on a live rabbit using the soft, smart contact lens. Left: Turn-on state of the LED in the soft, smart contact lens mounted on the rabbit’s eye. Middle: Injection of tear fluids with the glucose concentration of 0.9 mM. Right: Turn-off state of the LED after detecting the increased glucose concentration. Scale bars, 1 cm. (E) Heat tests while a live rabbit is wearing the operating soft, smart contact lens. Scale bars, 1 cm.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/4/1/eaap9841/DC1

    Supplementary Materials and Methods

    fig. S1. Fabrication processing steps of the hybrid substrate.

    fig. S2. AFM data analysis.

    fig. S3. Optical transmittance (black) and haze (red) spectra of the silicone elastomeric film.

    fig. S4. The variation of optical properties against mechanical stretching of the hybrid substrate (from 0 to 30% in tensile strain).

    fig. S5. Original image for the photograph test to identify the clarity of hybrid substrate.

    fig. S6. Wireless display circuit composed of an antenna, a rectifier, and an LED pixel.

    fig. S7. Fabrication procedures of wireless display on the hybrid substrate.

    fig. S8. Characteristics of the stretchable, transparent AgNF electrode as antenna.

    fig. S9. Characteristics of the Si diode and SiO2 capacitor.

    fig. S10. Sequential schematic images to transform to the lens shape.

    fig. S11. Mechanism of glucose sensing on graphene channel.

    fig. S12. The magnified real-time sensing result (at the first detection of glucose level) to verify the response time.

    fig. S13. Stability of the smart contact lens system.

    fig. S14. The relationship between the glucose concentration and luminance of the LED.

    fig. S15. SAR simulation result.

    table S1. Comparison with other noninvasive glucose monitoring technologies.

    movie S1. Embedding procedure of the hybrid substrate in the contact lens.

    movie S2. Wireless operation of wireless display with lens shape.

    movie S3. In vivo test of soft, smart contact lens for wireless operation.

    movie S4. In vivo test of soft, smart contact lens for heat generation test.

    References (4345)

  • Supplementary Materials

    This PDF file includes:

    • Supplementary Materials and Methods
    • fig. S1. Fabrication processing steps of the hybrid substrate.
    • fig. S2. AFM data analysis.
    • fig. S3. Optical transmittance (black) and haze (red) spectra of the silicone elastomeric film.
    • fig. S4. The variation of optical properties against mechanical stretching of the hybrid substrate (from 0 to 30% in tensile strain).
    • fig. S5. Original image for the photograph test to identify the clarity of hybrid substrate.
    • fig. S6. Wireless display circuit composed of an antenna, a rectifier, and an LED pixel.
    • fig. S7. Fabrication procedures of wireless display on the hybrid substrate.
    • fig. S8. Characteristics of the stretchable, transparent AgNF electrode as antenna.
    • fig. S9. Characteristics of the Si diode and SiO2 capacitor.
    • fig. S10. Sequential schematic images to transform to the lens shape.
    • fig. S11. Mechanism of glucose sensing on graphene channel.
    • fig. S12. The magnified real-time sensing result (at the first detection of glucose level) to verify the response time.
    • fig. S13. Stability of the smart contact lens system.
    • fig. S14. The relationship between the glucose concentration and luminance of the LED.
    • fig. S15. SAR simulation result.
    • table S1. Comparison with other noninvasive glucose monitoring technologies.
    • Legends for movies S1 to S4
    • References (43–45)

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • movie S1 (.mp4 format). Embedding procedure of the hybrid substrate in the contact lens.
    • movie S2 (.mp4 format). Wireless operation of wireless display with lens shape.
    • movie S3 (.mp4 format). In vivo test of soft, smart contact lens for wireless operation.
    • movie S4 (.mp4 format). In vivo test of soft, smart contact lens for heat generation test.

    Files in this Data Supplement:

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