A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry
This study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce u...
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MDPI AG
2017-01-01
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Series: | Sensors |
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Online Access: | http://www.mdpi.com/1424-8220/17/1/108 |
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author | Jin-Chern Chiou Shun-Hsi Hsu Yu-Chieh Huang Guan-Ting Yeh Wei-Ting Liou Cheng-Kai Kuei |
author_facet | Jin-Chern Chiou Shun-Hsi Hsu Yu-Chieh Huang Guan-Ting Yeh Wei-Ting Liou Cheng-Kai Kuei |
author_sort | Jin-Chern Chiou |
collection | DOAJ |
description | This study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce user discomfort, a capacitive sensor was embedded on a soft contact lens of 200 μm thickness using commercially available bio-compatible lens material and a standard manufacturing process. The results indicated that the reconfigurable sensor interface achieved sensitivity and baseline tuning up to 120 pF while consuming only 110 μW power. The range and sensitivity tuning of the readout circuitry ensured a reliable operation with respect to sensor fabrication variations and independent calibration of the sensor baseline for individuals. The on-chip voltage scaling allowed the further extension of the detection range and prevented the implementation of large on-chip elements. The on-lens system enabled the detection of capacitive variation caused by pressure changes in the range of 2.25 to 30 mmHg and hydration level variation from a distance of 1 cm using incident power from an RFID reader at 26.5 dBm. |
first_indexed | 2024-04-11T22:10:23Z |
format | Article |
id | doaj.art-ee421c4bf3d54e47832ea9fecb839f48 |
institution | Directory Open Access Journal |
issn | 1424-8220 |
language | English |
last_indexed | 2024-04-11T22:10:23Z |
publishDate | 2017-01-01 |
publisher | MDPI AG |
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series | Sensors |
spelling | doaj.art-ee421c4bf3d54e47832ea9fecb839f482022-12-22T04:00:35ZengMDPI AGSensors1424-82202017-01-0117110810.3390/s17010108s17010108A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout CircuitryJin-Chern Chiou0Shun-Hsi Hsu1Yu-Chieh Huang2Guan-Ting Yeh3Wei-Ting Liou4Cheng-Kai Kuei5Department of Electrical and Computer Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanDepartment of Electrical and Computer Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanInstitute of Electrical Control Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanInstitute of Electrical Control Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanInstitute of Electrical Control Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanInstitute of Electrical Control Engineering, National Chiao-Tung University, Room 617, Engineering Building 5, No. 1001, Ta Hsueh Rd., Hsinchu 30010, TaiwanThis study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce user discomfort, a capacitive sensor was embedded on a soft contact lens of 200 μm thickness using commercially available bio-compatible lens material and a standard manufacturing process. The results indicated that the reconfigurable sensor interface achieved sensitivity and baseline tuning up to 120 pF while consuming only 110 μW power. The range and sensitivity tuning of the readout circuitry ensured a reliable operation with respect to sensor fabrication variations and independent calibration of the sensor baseline for individuals. The on-chip voltage scaling allowed the further extension of the detection range and prevented the implementation of large on-chip elements. The on-lens system enabled the detection of capacitive variation caused by pressure changes in the range of 2.25 to 30 mmHg and hydration level variation from a distance of 1 cm using incident power from an RFID reader at 26.5 dBm.http://www.mdpi.com/1424-8220/17/1/108capacitance-to-digital converter (CDC)capacitive sensorsoft contact lensUHF RFID Class1 Gen2 |
spellingShingle | Jin-Chern Chiou Shun-Hsi Hsu Yu-Chieh Huang Guan-Ting Yeh Wei-Ting Liou Cheng-Kai Kuei A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry Sensors capacitance-to-digital converter (CDC) capacitive sensor soft contact lens UHF RFID Class1 Gen2 |
title | A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry |
title_full | A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry |
title_fullStr | A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry |
title_full_unstemmed | A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry |
title_short | A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry |
title_sort | wirelessly powered smart contact lens with reconfigurable wide range and tunable sensitivity sensor readout circuitry |
topic | capacitance-to-digital converter (CDC) capacitive sensor soft contact lens UHF RFID Class1 Gen2 |
url | http://www.mdpi.com/1424-8220/17/1/108 |
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