Dr Bhaskar Dudem

Energy harvesters for smart wearables are gaining increasing attention world-wide. Among the various type of options availabel, triboelectric nanogenerators harvesting mechanical energy from human body movements are especially attractive. In this work, a flexible sandwich-type triboelectric nanogenerator (FS-TENG) based on ridged and biocompatible silicone elastomers and thermoplastic polyurethane is proposed. The proposed FS- TENG exhibits the open-circuit voltages and maximum power density of ~80 volts and 0.35 mW/cm 2 , respectively. This preliminary performance already makes the device extremely promising to power low energy smart wearable devices, as well as monitor pressure in bespoke biomedical applications.

Electronic waste produced by plastic, toxic, and semiconducting components of existing electronic devices is dramatically increasing environmental pollution. To overcome these issues the use of eco-friendly materials for designing such devices are attaining great concern. This current work presents a recycled materials-based triboelectric nanogenerator (TENG) made of plastic waste and carbon-coated paper wipes (C@PWs), in which the PWs also collected from a waste bin. The resultant C@PWs-based TENG is then used for powering low-power electronic devices, and later, to generate a Morse code from a wearable for autonomous communication. Other end-users in a customized LabVIEW programme decode the Morse code signals and read the transmitted message. With further redesigning, a 9-segment keyboard is developed using nine-TENGs, connected to an Arduino controller to display the 9-segment actuation on a computer screen. Based on the above analysis, our C@PW-TENG device is expected to have an impact on future self-powered sensors and IoT systems.

Strategies to maximize the surface charge density across triboelectric layers while protecting it from humidity are crucial in employing triboelectric nanogenerators (TENGs) for commercial/real-time applications. Herein, for the first time, we propose the utility of crystalline silk microparticles (SMPs) to improve the surface charge density in materials like polyvinyl alcohol to realise its applicability for TENG devices. Moreover, these SMPs are extracted from discarded Bombyx mori silkworm cocoons by facile, inexpensive, and single-step alkaline-hydrolysis treatment. We examine the performance of these composites with counter-materials composed of waste PTFE plastic cups to show reuse in recycled products. The processing cost of TENG developed from recycled materials is not only low but eco-friendly. The TENG performance as a function of the concentration of SMPs is investigated and compared with the composite's work-function and surface-potentials, with the distance-dependent electric field theoretical model employed to optimize the performance. Consequently, the optimized TENG exhibits maximum output voltage, current, charge, and power density of ∼280 V, 17.3 μA, 32.5 nC, and 14.4 W·m−2, respectively, creating a highly competitive energy harvester that can conform to the rigorous needs of wearables and mobile applications. Furthermore, the fully packaged silicone rubber device protects it from humidity and enables the device utility for practical applications with a soft, comfortable, and skin-friendly interface.

Triboelectric nanogenerators (TENGs) developed using eco-friendly natural materials instead of traditional electronic materials are more favorable for biocompatible applications, as well as from a sustainable life-cycle analysis perspective. Microarchitectured silkworm fibroin films with high surface roughness and an outstanding ability to lose electrons are used to design TENGs. An alcohol-annealing treatment is utilized to strengthen the resistance of the silk film (SF) against humidity and aqueous solubility. Herein, for the first time, the distance-dependent electric field theoretical model is employed to optimize the TENG parameters to achieve high output, which shows excellent agreement with the experimental outputs of SF-based TENG. The alcohol-treated microarchitectured SF (AT-MASF) with a polytetrafluoroethylene positive contact exhibits a stable and high electrical output even in harsh environments. These studies can lead us closer to the attractive future vision of realizing biodegradable TENG systems for harness/sensing various biomechanical activities even under real/humid environments. The potential and real-time application of the proposed AT-MASF-based TENG is demonstrated by directly employing its electric power to drive a number of low-power portable electronics and for sensing in human-body centric activities.

Electronic waste produced by plastic, toxic, and semiconducting components of existing electronic devices is dramatically increasing environmental pollution. To overcome these issues, the use of eco-friendly materials for designing such devices is attaining much attention. This current work presents a recycled material-based triboelectric nanogenerator (TENG) made of plastic waste and carbon-coated paper wipes (C@PWs), in which the PWs are also collected from a waste bin. The resultant C@PW-based TENG is then used for powering low-power electronic devices and, later, to generate a Morse code from a wearable for autonomous communication. In this application, the end users decode the Morse code from a customized LabVIEW program and read the transmitted signal. With further redesigning, a 9-segment keyboard is developed using nine-TENGs, connected to an Arduino controller to display the 9-segment actuation on a computer screen. Based on the above analysis, our C@PW-TENG device is expected to have an impact on future self-powered sensors and internet of things systems.