A Micropillar‐Assisted Versatile Strategy for Highly Sensitive and Efficient Triboelectric Energy Generation under In‐Plane Stimuli

For the application of portable and wearable devices, the development of energy harvesters sensitive to various types of local and subtle mechanical displacements is essential. One of the most abundant but difficult‐to‐harvest mechanical energies in everyday life is the in‐plane kinetic energy that arises from a rubbing motion. Here, an efficient method is proposed to generate electrical energy from tiny horizontal forces by laminating microstructures on a conventional triboelectric nanogenerator (TENG). The microhairy structures serve to induce contact friction between the two dielectric materials, driven by reversible mechanical bending when a contact rubbing pressure or noncontact airflow is applied in the horizontal direction. Compared to TENG devices without microstructures, the introduction of microstructures greatly enhances the energy harvesting in the same situation. In addition, the TENG device with micropillars can generate electrical output under tiny mechanical variations (