Hierarchical surface patterning for triboelectric nanogenerators and sensors

We develop PDMS and PMMA triboelectric surfaces with micro/nanopatterning via simple and effective methods, and starting from Si substrates anisotropically etched with low KOH concentration solution. A hierarchical structure formed by micro-pyramidal structures with superficial nano-roughness, is developed in a 200 μm PDMS layer. In parallel, by means of a PDMS stamp and nanoimprinting technology, a 2 μm film of PMMA is nanopatterned, showing the feasibility of large scale production of such surfaces using a cost effective and easily repeatable process. We show SEM and AFM characterization of the negative (PDMS) and positive (PMMA) triboelectric surfaces and demonstrate how contact keys, integrating the fabricated soft materials, can be used to investigate the signals generated from the repetitive mechanical stimulation of its taxels.