Additive Manufacturing of Bearing Inspired TENGs for Integrated Energy Storage

With the recent advancement in soft, flexible, and wearable devices, the need for innovative energy sources increases rapidly to overcome the energy needs for such devices. The capabilities of conventional energy storage devices may be insufficient to meet the energy needs of these devices. The solution to this problem may be to improve the performance of storage devices or their integration with energy harvesters. These harvesters include photovoltaics, piezoelectric, electromagnetic, and triboelectric nanogenerators (TENGs). Among these devices TENGs stand out with their unique features such as adaptability, simple-structure, high power density and integrability to modern devices. However, there are some problems that hinder the widespread applicability of TENGs. One of these problems is the breakdown voltage of the air, which acts as a barrier to obtain high power density. Recent studies suggests that the use of lubricants can increase this breakdown voltage while providing polarization between electrodes to improve their performance. In this work, an innovative, bearing inspired TENG (Bi-TENG) design was explored using polylactic acid (PLA) fused deposition modeling. The effect of lubricant and rotation speed on the performance of Bi-TENG was investigated. A peak power of 20 µW was obtained from the fabricated Bi-TENGs and the addition of lubricant was found to increase power by 110% compared to non-lubricated Bi-TENG. The fabricated TENG was also used to charge energy storage devices to demonstrate its use in wearable applications.