Research Projects

Next-Gen Ambient Vibration Energy Harvesting (VEH) System

Typical vibration energy harvesters (like a piezoelectric cantilever) are essentially a spring-mass-damper systems and their natural resonant frequency needs to be matched to that of external host excitation (think machine surface vibrating at line frequency). Further, the performance is  abysmal for irregular excitation (think bridge vibration due to vehicle movement). We are co-developing  active mechanical control and non-linear switched electrical interface circuits for 'plug & play' frequency-agnostic fundamental-power-limit vibration energy harvester systems.    

Power Extraction Circuits for Triboelectric and Piezoelectric VEHs

Triboelectric Nanogenerators (TENGs) and Piezoelectric harvesters with low electromechanical coupling coefficient can provide multi-fold power gain through synchronous switched circuit (SSC) based extraction over simple minded full-wave-rectifier. We are developing novel SSC topologies followed by their mathematical modeling, and simulation/experimental based verification. We are pursuing both discrete-component and on-chip design; specific focus is SSCs for TENGs in high-voltage (70V and upwards) process nodes.

Multi-Input Multi-Output (MIMO) Energy Harvesting PMIC

We plan to pursue a general purpose Energy-Harvesting Power Management Integrated Circuit (EH-PMIC) that is seeing a widespread academic and industrial interest. Such an EH-PMIC provides single-stage to receive power from multiple modality energy harvesters with AC or DC output, satisfy their respective MPPT requirements, and deliver power at regulated DC voltages for the end-load sub-systems.

Ultrasonic Wireless Power Transfer (WPT)

Ultrasonic WPT involves the transfer of energy through the means of mechanical (acoustic) waves and offers superior power transfer efficiency compared to the standard inductively coupled WPT method for certain mediums, especially at larger transmission distances and hence a promising solution for powering IoTs deployed underwater, embedded in concrete structures, and biomedical implant. We are targeting end-to-end US-WPT system with VEH receiver and PMIC optimized for ultrasonic frequency operation. Interestingly, swapping the VEH with an antenna and designing the circuit for even higher frequency (in GHz!) gets us a RF-powered batteryless sensor (think WiFi or 5G signal harvesting batteryless sensor) and is also a topic of future interest for us.  

Digital Low-Dropout (LDO) Voltage Regulators

Digital LDOs have emerged as robust and scalable alternative to their analog counterparts. In this collaborative project, we are exploring novel topologies/control schemes for Digital and Mixed-mode LDOs to reduce quiescent-power and simultaneously achieve high FoMs.