Self-powered Flexible PDMS Channel Assisted Discrete Liquid Column Motion Based Triboelectric Nanogenerator (DLC-TENG) as Mechanical Transducer

Abstract

Fluid flow in small scale channel as droplet, continuous or discrete volume of liquid has been used in the multidisciplinary research field to be utilized in wide variety of applications in chemistry, biology, medical technologies. Recently, energy scavenging technique that merges the microfluidics with liquid–solid contact electrification charging from the small flows has become a new area of investigation to be applied as sensory module. In this article, a flexible fluid based mechanical sensing element using the triboelectrification of the oscillatory discrete volume of liquid flowing inside the hydrophobic mini channel over PTFE polymeric film is described. To achieve the high output efficiency and to reduce the wettability of the channel, micropatterned PDMS surface was implied for smooth operation and constant power output of the device. Pressure gradient was applied for the forward–backward motion of the liquid column over the free-standing mode porous PTFE thin film-based electrode and a maximum of 10 nA of short circuit current and 20 mV of open circuit voltage was achieved at 40 mbar pressure and frequency of 1 Hz. Finally, the flexible DLC-TENG shows better performance as a transducer to be effectively used in measuring the frequency response to the angular displacement of the rotary actuator consequently pressure fluctuation sensing. The obtained results are promising whereas counting nominal deflection of pressure such as in the robotic manipulator or actuator is regarded as an essential factor.