Publications OK SMART LAB

Scissorable piezoelectric nanogenerators comprising flexible micrograting electrodes interconnected by laterally aligned ZnO nanowires for size-customizable devices
Authors
Minwook Kim, Donghyun Lee, Kwanlae Kim, and Jong G. Ok
Journal
EcoMat
Vol. (No.), pp.
8 (3), e70058 (Mar 2026)
Year
2026
We present a “scissorable” piezoelectric nanogenerator (SCIPENG) platform comprising flexible micrograting electrodes laterally interconnected by piezoelectric nanowires, whose scalable and homogenous architecture uniquely allows easy cut into the desired size simply by using a scissors. On each sidewall of the microgratings formed by UV nanoimprint lithography, Ag and Au are sequentially deposited via glancing angle deposition (GLAD), followed by another GLAD of Cr on top of the microgratings. Through the metal-mediated seedless hydrothermal synthesis, the ZnO nanowires (ZNWs) can be laterally grown preferentially from each Au sidewall to interconnect each neighboring Ag sidewall while a catalytic-inactive Cr capping layer securely suppresses unnecessary ZNW growth outside the micrograting scaffold. The resulting SCIPENG structure, consisting of multiple stacks of laterally aligned ZNW-interconnected, Au- and Ag-deposited asymmetric micrograting electrodes, exhibits excellent piezoelectric performance under repeated mechanical bending without external bias, with the maximum peak-to-peak voltage of ~140 V. Scissoring into the controlled sizes (e.g., half-length, half-stack) demonstrates well-predictable scaling behavior; output voltage increases with decreased micrograting length; current scales linearly with the stacking number of microelectrodes. This platform offers highly scalable fabrication and extremely easy scaling, particularly promising for sustainable high-mix, low-volume production of flexible devices requiring diverse sizes upon diverse uses.