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This paper reports the microfabrication of a Galinstan-based flexible coil on a contact lens and its preliminary use for wireless power transfer onto a smart contact lens. The Galinstan-based coil provides accommodation against physical deformation of a contact lens by maintaining electrical conductivity under strains due to its semi-fluidic nature. The fabricated Galinstan-coils successfully demonstrated post-deformation tolerance up to 166.67% strain. The fabricated contact lens prototype with a Galinstan-coil showed the maximum wireless power reception of 32.4 μW with a power efficiency of 0.75% from an external coil located 5 mm away within a frame of eyeglasses.
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Energy and Accuracy Characterization of a Burst-Mode Range Sensing Approach for Smart Contact Lenses
In this paper, we present the characterization of a new range sensing approach for use in emerging smart contact lens applications. Smart contact lenses offer a promising approach to treating the most common form of vision loss by using a tunable lens to accommodate for focal errors. A range sensor is an integral component of the system because it estimates an object's distance from the user in order to determine the target focal length. We performed an empirical study with custom fabricated coils in a mock eyeball setup to understand the energy-accuracy trade-offs of a burst-mode sensing approach based on transmission and reception of square pulses between the coils. We wirelessly transmitted square pulses between the coils and estimated the range of an object by sensing the received voltages and inferring the angular relationship between the two contacts. We demonstrate a functioning range sensing approach that can be implemented with energy as low as 1.8 nJ per measurement with at least 95% accuracy.
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- Award ID(s):
- 1932602
- PAR ID:
- 10402733
- Date Published:
- Journal Name:
- 2022 IEEE Sensors
- Page Range / eLocation ID:
- 1 to 4
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/SENSORS52175.2022.9967207
