Size effect on the output of a miniaturized triboelectric nanogenerator based on superimposed electrode layers

Traditional methods enhancing the output performance of triboelectric nanogenerator (TENG) are mainly by increasing the number of single TENGs mechanically after controlling the materials surface structures and/or chemical modifications. We present an innovative TENG superimposed electrode layers by utilizing the edge effect of two charged parallel plates with poly-l-lactide (PLLA) slice and silicone sheet as the triboelectric materials and the extended part of Al electrode as the connection. When the gap distance (d) between the upper and lower friction surfaces is 1.5 cm, the d/L (L is the lateral size of TENG) is greater than 0.4, the short-circuit current (I-sc) of TENG stacked with four layer electrodes was 3 times larger than that of TENG with one layer electrode. The I-sc reaches a saturation when the number of superimposed electrode layers was beyond eight, corresponding to 3-5 times larger than that with one layer electrode. While the obtained I-sc was 2-5 times larger than that with one layer electrode, the volume of TENG based on superimposed electrode layers can be reduced by 50-80% compared to the traditional TENGs stacked the number of single TENGs. This simple, novel method paves a way for enhancing output current, more miniaturization of the TENG.