StimDust (stimulating neural dust) is a mm-scale, batteryless implant that is wirelessly powered and controlled through ultrasound. Ultrasonic energy can easily propagate through tissue allowing StimDust to be implanted deep in the body (>5cm). A low-power IC interprets the incoming ultrasound and generates controlled stimulation patterns to activate (or inhibit) the nerve.
NMIC & WAND
CMOS Microelectrode Arrays
In dense neural tissue, the isolation of single unit activity (spiking) is extremely difficult with a single recording site, meaning densely-packed (cellular scale), multi-site recording arrays are required for cell localization and sorting. Microelectrode arrays (MEAs) simultaneously acquire electric field activity across relatively large areas of neural tissue. Increasing the number of electrodes allows for more simultaneous single-cell recordings as well as spatially broad analysis of local field potentials (LFPs) that provide insight into how and under what conditions neuronal ensembles synchronize activity. The channel count of active CMOS MEAs can be drastically increased relative to passive arrays (fanout-constrained) by locally multiplexing channels onto fewer wires.
Coupled-Oscillator Networks in the Olfactory Bulb
Oscillatory (coherent) neural activity within and between brain structures are ubiquitous, present in both normal and aberrant brain function. For sensory processing in the olfactory bulb, these oscillations are implicated as a “clock” for robust, timing-sensitive computation of multi-dimensional inputs. While gamma-band activity is intrinsic to the olfactory bulb in mammals, the circuitry that drives these oscillations is unclear. Using slices on MEAs, we discovered the presence of independent, intracolumnar (i.e. local) oscillators. We induced persistent (minutes) gamma oscillations using neurochemical activation and optogenetic stimulation of olfactory sensory neuron axons.