NEMO: Neural Electro-Mechano-Optic Sensors for Multiplexed Neural Interfaces

TL;DR

The paper presents a new ultra-compact electro-optomechanical neural sensor that enables high-resolution, multiplexed neural recordings with minimal artifacts, suitable for use in freely moving subjects.

Contribution

Introduction of a miniaturized electro-optomechanical sensor using NEMS technology for improved neural signal detection and multiplexing capabilities.

Findings

Achieved a detection limit of 110 microvolts.

Demonstrated successful benchtop and ex-vivo neural recordings.

Eliminated the need for bulky headstage equipment.

Abstract

We introduce a novel electro-optomechanic neural sensor for realizing ultra-compact neural recording probes that can detect and relay electrophysiology signals from within neural tissue. This technology addresses outstanding challenges faced by existing neural recording technologies, including the resolution trade-off with signal-to-noise-ratio (SNR) due to the high impedances of small electrodes, and lingering stimulation artifacts. The sensor employs a highly miniaturized NEMS (nano-electromechanical systems) electrostatic transducer that modulates a silicon photonic microdisk resonator to convert electrical signals to an optical signal modulation. We have been able to achieve a limit of detection down to 110 microvolts, making the sensor sensitive enough to detect neural signals. This sensitive electro-optomechanic sensor directly detects electrophysiology signals and converts them to optomechanic modulation for effective transmission to outside the brain, which provides the unique potential for massive multiplexing of neural recordings. This design eliminates the need for bulky backend headstages that limit neural recording on awake free-roaming subjects. The ability of the device to record electrophysiological signals has been demonstrated using benchtop characterization and ex-vivo recordings from live neural tissue.