Fig. 2: Structural optimization, working principle, and performance of the BPCL.
a The snowflake-inspired BPCL consisting of inner plate and outer fractal dendrite exhibits self-similarity with the natural snowflake. b The fractal star-polygon structure with a different Dn. c Voltage output comparison of PEGs with a different Dn (4, 6, 8, 12, and 30) at a frequency of 1 Hz. d Radar chart of different PEGs for performance comparison. e Schematics of the working principle of the BPCL under different eye blink stages (i-iv), R represents the rectifier. f VD recorded from the BPCL under different pressure and frequencies, n = 3 independent samples. g VD recorded during blink in vivo. h Long-term stability test of the BPCL. i Top-view and j side-view AMFES simulated EF distribution inside a cornea. k Vertical and l Horizontal EF strength as a function of the depth and width extrapolated from Fig. 2j. The corneal injury area was marked within the dashed box. All data in (f) are presented as means ± SD. BPCL blink-driven piezoelectric contact lens, Dn dendrite number, Vpp peak-to-peak voltage, TAE top aluminum electrode, BAE bottom aluminum electrode, VD the voltage difference between the ITO electrodes, EF electric field.
