Flexible Electrostatic Energy Harvester Driven by Cyclic Eye Tear Wetting and Dewetting

We present the fabrication and experimental results of a flexible electrostatic energy harvester chip suitable for a smart contact lens application. The harvester consists of a variable area liquid capacitor formed between a hydrophobic film on the flex substrate and the rolling meniscus of a non-wetting eye tear drop. The harvester was tested under tear sliding motion emulating eyelid blinking. The 2×10 mm2 harvester generated 1.36 µJ of energy per blink and average power of 0.265 µW when pre-charged at 6 V and driven at typical blinking velocity conditions.