Tin disulfide piezoelectric nanogenerators for biomechanical energy harvesting and intelligent human-robot interface applications

Tin disulfide nanosheets (SnS₂ NSs), belonging to a new family of layered metal dichalcogenides, have evoked considerable attention in multidisplinary scientific applications because of their high electron mobility, excellent chemical stability, and wide accessibility to optoelectronic devices. However, despite the prediction of SnS₂ to possess excellent piezoelectricity, only very few attempts have been made to investigate the electromechanical characterisitcs of SnS₂. Herein, we report the experimental investigation of the intrinsic piezoelectricity of SnS₂ NSs, which were synthesized with a facile chemical vapor deposition (CVD) method. The prominent inverse piezoelectricity of SnS₂ NSs was measured via piezoresponse force microscpoy (PFM). To further evaluate the piezoelectric performance, SnS₂ NSs were integrated into a piezoelectric nanogenerator (PENG) device to display the energy harvesting and active sensing capabilities. Most importantly, the SnS₂ PENG device was utilized to explore the synchronous human-robot control of a smart sign language system, which demonstrates great potential for the future applications in human-machine interface and enabling sensing technology.