Research Projects

The IoT-based remote structural and machine health monitoring enables predictive maintenance, avoiding costly down-time and catastrophic failures. A challenge with such wireless sensor nodes is their limited battery-life, requiring frequent battery replacement, and increasing the maintenance cost. Integrating an ambient micro-power vibration energy harvester to self-power and realize ‘place & forget’ sensor nodes is a ‘green’ and maintenance-free solution. Triboelectric Nanogenerator (TENG) is a promising vibration energy harvesting technology based on contact-electrification and subsequent electrostatic induction that has emerged as a cost-effective alternative to the standard piezoelectric-based harvesting. A key challenge plaguing the wide-scale commercial adoption of this technology is poor efficiency of power extraction circuit (PEC) that interface the TENG with IoT’s energy storage (battery/capacitor). The PEC needs to be designed considering (source) TENG's challenging characteristics: high open-circuit voltage (in tens to hundreds of volts), low short-circuit current (due to low capacitance), and non-linearly time-varying internal capacitive impedance and achieve (optimized) maximized power extraction under changing external vibration conditions (accordingly, the TENG parameters). The key objective of this proposal is to design and prototype a complete end-to-end power management solution for interfacing any given TENG with a DC load (for example, microcontroller based IoT sensor) in form of a plug-and-play power management integrated circuit (PMIC). For the same, a novel power extraction technique that maximizes the power under a given circuit breakdown voltage limit surpassing the state-of-the-art designs will be developed based on the mathematical modelling of TENG energy transduction. A novel synchronous switched circuit architecture will be developed for the extraction technique’s on-chip implementation in a high-voltage BCD technology, leveraging our previous experience in design of PECs for TENG and Piezoelectric harvesters. Post design, simulation-based testing, and layout, PMIC will be taped-out using a multi-project-wafer (MPW) service. Next, taped-out PMIC will be interfaced with a custom developed in-lab TENG setup for experimental testing. Finally, we will prototype the end-to-end system, integrating a sensor node, and demonstrate batteryless wireless transmission of sensor data.