Effective and Accurate Approach for Measuring Key Parameters in Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) exploit the triboelectricity of several materials/structures together with an appropriate device architecture to harvest mechanical energy. These devices usually present high output voltages, high internal impedance, and low output currents, and as oscilloscopes are limited by relatively low input impedance, their analysis requires specific instrumentation for the assessment of the main key figures of merit. Due to the increased research interest on this topic, the development of electronic circuits for a rapid and accurate evaluation of the TENGs performances has become urgent. Here, we propose the development of an electronic circuit implemented on a small footprint printed circuit board (PCB) board. This circuit is based on a differential amplifier probe scheme and is a compact and cost-effective approach able to measure both the TENGs outputs: open-circuit voltage at a very high resistive load and short circuit current. Additionally, it offers the possibility to measure voltages under different high resistive loads allowing the assessment of the power behavior of the device. To prove the effectiveness of this approach, triboelectric devices based on carboxymethyl cellulose (CMC) porous aerogel films have been fabricated and analyzed. Furthermore, experimental results in terms of short-circuit currents have been compared with those obtained by using a commercial low noise current amplifier. This approach allows to rapidly and accurately evaluate the behavior of a specific triboelectric device and to effectively compare devices having different characteristics, thus accelerat- ing the development and applications of TENGs.