3D Printed Flexible Triboelectric Energy Harvesters via Conformal Coating of Parylene AF4

For the first time, a 3D-printed flexible and wearable triboelectric energy harvester (TEH) is presented based on the 3D printing of polyurethane (PU) and a conformal coating process using Parylene AF
₄
. The key advancements of this work include: (1) the usage of the stereolithographic (SL) 3D printing process for the prototype of a multiple-layer energy harvester to increase the active surface areas; (2) the deposition of the high surface charge density material of Parylene AF
₄
with a conformal coating process to act as the active layer. The experimental results for a prototype triple-layer device show a peak short circuit current (SCC) of 390nA and a peak power density of 5.5μW/cm
²
. As such, this work can potentially open up a new class of energy harvesters based on 3D printing technologies for arbitrary geometries for applications such as shoe soles.