Analysis of textile based triboelectric nanogenerators (T-TENG)

Nanotechnology-focused energy harvesting, energy conversion, energy storage and application areas are constantly evolving with the increasing demand for renewable energy. In this context, triboelectric nanogenerators (TENG) with the capacity to convert mechanical energy into electrical potential have emerged as innovative devices. TENG systems are the second generation of mechanical energy harvesting systems and in recent years some TENG systems operating in contact separation mode have managed to achieve high power densities. Considering that the human body has more than one energy source that can be harvested, intensive studies have begun on textile-based wearable TENG systems. In this thesis, the performance characteristics of TENG systems based on textile materials and the effects of textile materials on energy harvesting were investigated. A horizontal TENG test device was designed for use in sliding mode and a vertical TENG test device was designed for the vertical contact-separation mode. Different T-TENG structures were formed. Woven fabrics containing wool, polyamide 6.6, polyamide 6 and bio-based polyamide fibers were produced and used as positive dielectric surfaces. Silicone film, PTFE film, PTFE fabric and PI film surfaces were used as negative triboelectric surfaces, and the energy efficiency harvested from these material pairs was examined. The effects of material type, surface area, impact frequency, impact force and distance between dielectric surfaces on the triboelectric voltage values of these structures were investigated. It has been shown that the triboelectric character of the fibers, fabric thickness, porosity and surface structure, impact frequency, impact force and separation distance have critical effects on the average voltage value of woven based TENGs, confirming previous studies. In respect of experimental measurements, the highest average voltage value was obtained in the contact separation (CS) triboelectric mode between PTFE and PI film materials which tend to be negatively charged due to a relatively low dielectric constant, and woven fabrics containing PA6.6 and/or PA6. The highest average voltage value measured was 252 mV while the highest average current was 210 nA. Keywords: Triboelectric Nanogenerator (TENG), Textile Based Triboelectric Nanogenerator (T-TENG), Vertical Contact Separation Mode, Woven fabric