Compressibility Effect of Charge Generating Layer on Output Performance of Triboelectric Nanogenerator

Triboelectric nanogenerator (TENG) that can be used in next-generation wearable devices, have received great attention due to their simple device structure and low cost. Among many factors to affect the output of TENG, the compressibility of a charge generating layer becomes very important, because it influences the contact area as well as the number of induced charges. Nevertheless, it has been challenging to achieve high compressibility with conventional polymers due to the intrinsic entanglement of polymer chains. To significantly reduce the entanglement of polymeric materials for achieving low compressive modulus (<i>E</i>) or high compressibility, we chose bottlebrush polymers. Our study leverages bottlebrush elastomers, which suppress chain entanglements—an effect that significantly lowers various mechanical moduli compared to conventional linear polymer networks. We found that TENG output performance such as voltage, current and surface potential, are increased with decreasing <i>E</i> of the charge generating layer. When we used crosslinked bottlebrush poly(dimethyl siloxane) (PDMS) as a charge generating layer of TENG device, the output voltage (120 V) was more than twice larger than that (55 V) of conventional crosslinked PDMS without having bottle brush. These results demonstrate the power of controlling polymer architecture in the context of advanced electronic applications.