Neural Interfaces

Neural interfaces are generally categorized as systems which enable direct communication between the cortex and an external device. Such systems could be used for monitoring and treating neurological disorders like epilepsy, studying and treating neurodegenerative disorders and also for allowing tetraplegic patients to control neuroprosthetic devices. Neural Interfaces will play a vital role in restoring sensory function, communications, and control in impaired humans. Designing low-power circuits and efficient algorithms are essential parts of making these systems robust and wearable.

With respect to Neural Interfaces, our lab focuses on three main areas of research:

 

 

Location-Broadcasting Chips

We present an alternative approach to microscale device localization based on concepts from nuclear magnetic resonance. In particular, the magnetic-field-dependent precession frequency of nuclear spins allows their location in space to be encoded through the application of magnetic field gradients. This allows MRI to visualize signals from nuclear spins located throughout a specimen with ~100 µm resolution.

3D-Integrated High-sensitivity Optical Receiver

Increasing Silicon integration leads to better performance in optical links but necessitates a corresponding co-design strategy in both electronics and photonics. In this project a 3D-integrated CMOS/Silicon-photonic receiver is presented. The receiver is specifically designed to take advantage of low-cap 3D integration and advanced silicon photonics.

Fully Implantable Glucose and Lactate Sensor

Miniaturization of implantable biosensors for continuous, in vivo monitoring of clinically relevant analytes is an important step toward viability of such devices. While wireless power delivery via on-chip antennas promises miniaturization and realization of minimally invasive devices, it can only support low levels of power consumption. This is due to the significant tissue absorption at high frequencies, small size of the chip and quality factor of on-chip inductors. Therefore, reducing the power consumption of the sensor while maintaining high sensitivity and dynamic range is crucial.

Origami Biomedical Implants

Origami implant design is a 3D integration technique which addresses the size and cost constraints in biomedical implants. Large systems can be split into multiple chips and connected using 3D integration techniques to be folded compactly for implantation and unfolded inside the body. Electronics can be partitioned into functional blocks for mass-production and customs implants can be assembled from these relatively cheap modules.

PTAT Temperature Sensor for Micro-Ring Resonator Stabilization

As the resonance wavelength of micro-ring modulators is susceptible to temperature fluctuations, they require thermal tuning. The power consumed by wavelength stabilization circuitry is often higher than the transmitter itself. In this project a monolithic PTAT temperature sensor is proposed for low-power thermal stabilization of micro-ring resonator modulators through direct measurement of temperature.