Current Projects
ASIC integrated graphene Hall-effect magnetic sensor system
There is a constant need for Hall-effect magnetic sensors with lower noise and lower offset for the high-accuracy analog applications driven primarily by industrial and automotive markets, for example, high dynamic range current sensing for battery management in electric vehicles. Graphene-based Hall sensors (GHSs) demonstrate low thermal noise due to their high carrier mobility but suffer from large low-frequency flicker noise and offset limiting the prevalent low-frequency applications. We have proposed a gate modulation scheme for GHSs that uses dynamic ambipolar operation to up-convert the input magnetic signal to higher modulating frequencies while the offset and flicker noise remain spectrally unchanged and thus enabling thermal noise limited performance. We are currently developing an ASIC to be integrated with GHS for a low-noise, low-offset magnetic sensor system.
Chip-scale Nuclear Magnetic Resonance (NMR) system
Nuclear Magnetic Resonance (NMR) is a well-known and popular technique that allows the molecular structure of a material to be analyzed by observing and measuring the interaction of nuclear spins when placed in a strong magnetic field. In recent times, low-field NMR systems using small permanent magnets have been the focus of considerable research due to their portability and wide range of applications. We are trying to develop an ASIC-based, portable NMR system that improves the state-of-the-art in terms of resolution, sensitivity, noise, and power performance.