Investigating fundamental contact mechanics and performance of Tribo-electric Nano-generator from human movement

Supervisor: Dr Satyaranjan Bairagi and Dr Charchit Kumar

Industry Partner: Kymira and WeirAdvanced Research Centre, University of Strathclyde

School: Engineering

Description:

The world’s energy demand is growing at an alarming rate of up to 2% every year. At the same time, the global climate emergency demands that we limit carbon emissions and secure new clean and sustainable energy solutions. As our society advances toward a 'smart world,' where sensors, wireless technologies and miniaturized self-powered devices gain greater importance, the demand for distributed energy sources with reduced carbon emissions becomes increasingly evident. Often daily-use electronic devices which do not need large power use Lithium-ion and other batteries which have limited lifetime, and high environmental impact at the end of life. The recent emergence of Triboelectric Nanogenerator (TENG) technology has provided a potential alternative. They can be fabricated from reusable/compostable materials making the module fabrication more sustainable. 

First invented in 2012, TENGs have drawn considerable attention from researchers in recent years. TENGs convert mechanical energy into valuable electrical energy based on two key phenomena triboelectrification (charge transfer across the contacting interfaces) and electrostatic induction (induced charge on backing electrodes). TENG operation relies on an oscillating contact – separation scenario. TENGs have a wide range of uses, and the rightful incorporation of TENG generators into shoes holds a significant potential. Typically, human footsteps (walking or running) produce about 20W biomechanical energy. If this pervasive energy source is utilised effectively, it can hold the potential to independently harvest electrical power with sustainability benefits. Prior attempts have been made using piezoelectric energy generators (PEGs), but the low power density (ranging from 0.001 mW/cm2 to 1 mW/cm2) of PEGs is a major limitation. In contrast, TENG harvesters have significantly higher power density (about 100 mW/cm2).  

The Materials and Manufacturing Research group have recently developed lightweight high electrical performance TENGs, which could positively be incorporated into the proposed Smart Shoe. Recent developments in Additive Manufacturing (AM) offer various innovative ways to produce highly complex structures with internal features in various materials including flexible polymers (suitable for this project). Moreover, AM also provides an attractive route for integrating miniaturized electronic devices with non-conventional objects keeping durability and automation in mind. As compared to using discrete wires to connect various electronic components in the proposed Smart Shoe, 3D printed metallic interconnects on the sole are expected to make the system more compact and durable. Key aspects of endurance and electrical output stability of the final developed technology needs systematic field testing. Introduction of AM and corresponding testing of AM components will be in the focus of the proposed internship project.