During the research activities of the project, it was found out that by employing time-domain signal processing (TDSP) for realizing required functions in neural recording implants, it is possible to achieve up to three orders of magnitude (up to 1000 times less) energy dissipation reduction in neural recording and sensing implants. In addition to the energy dissipation reduction properties of TDSP, it was discovered that by employing the time-domain operation concept, extremely sensitive measurement circuits can be built. A proof of concept microchip was implemented to investigate the ingress of the water molecules and ions when a biomedical implant is placed inside a biological body.
As the proposed time-domain proof of concept, a wireless neural recording microchip was developed and implemented. The implemented microchip achieves three orders of magnitude lower energy dissipation when compared to the other implementations in the literature. Time-domain operation was further utilized to create extremely energy efficient sensors for future multi-modal sensing biomedical implants. The time-domain sensors implemented during the course of the project will allow future bioelectronics implants to measure light (similar to an image sensor), temperature, extremely small electrical currents, and ion concentration and electro-chemical properties of liquids and tissues with the least amount of energy while being implemented using low-cost standard CMOS technologies.
Finally, time-domain operation was used for creating an extremely energy efficient artificial neural network (ANN) implementation, which reduces the energy dissipation by an order of magnitude when compared to the most energy efficient implementation in the literature.