Contact Area of Electrification Materials Relating to Triboelectric Generators: A Comparative Study

Triboelectric generators (TEGs) stemming from the triboelectric phenomena, are promising for energy harvesting due to their high output power and efficiency. Analysis of the tribo material selection for TEGs has suggested that energy generation is linked to heterogeneous and homogeneous materials found at opposite ends of the triboelectric series. Current research has identified that the triboelectric phenomenon also exists from contact between identical tribo materials with the advancement of surface modification. However, a comparison of composite and identical homogeneous TEGs has yet to be reported. For this research, organic polymer membranes Polyamide-6 (PA6) and Polytetrafluoroethylene (PTFE) were evaluated. The membranes were cut into samples of varying dimensions to build three sets of TEGs for comparison. Two identical sets of four sampled TEGs were fabricated using the same membrane (i.e., PA6-PA6 and PTFE-PTFE); in contrast to a composite set of four sampled TEGs made from the two distinct membranes (i.e., PA6-PTFE). By repeatedly sampling the TEGs in sliding mode at a speed of 0.2 m/s and with a vertical force of 9.8 N an open circuit voltage (V_oc) was generated and recorded. As a result, the V_oc of the identical TEGs was compared to the V_oc of the composite TEG in which the tribo materials are located at opposite ends of the triboelectric series. It was also observed that the V_oc increased almost linear in relation to the surface area of the TEGs; thus, suggesting that the surface area of the TEG can influence significantly the V_oc to a great extent.

Graphical abstract