Fully Wireless ASIC With MagSonic Operation Using Magnetoelectric Transducer for Neural Stimulation and Recording.

Area of Science:

• Biomedical Engineering
• Neurotechnology
• Integrated Circuit Design

Background:

• Wireless neural interfaces are crucial for advanced brain-computer interfaces.
• Existing systems often face challenges with power delivery, data transmission, and miniaturization.
• Magnetoelectric (ME) transducers offer a promising modality for wireless power and data transfer.

Purpose of the Study:

• To present a wireless application-specific integrated circuit (ASIC) for neural stimulation and recording using the MagSonic modality.
• To demonstrate a compact, integrated solution requiring minimal external components.
• To validate the ASIC's performance in terms of power, stimulation, and recording capabilities.

Main Methods:

• Fabrication of a 180 nm CMOS ASIC integrating power management, a biphasic AC stimulator, and neural recording/uplink circuits.
• Utilizing a magnetoelectric (ME) transducer for wireless power transfer (length mode) and data communication (thickness mode).
• Characterization of power reception, stimulation voltage tolerance, and neural signal transmission rates.

Main Results:

• The MagSonic ASIC achieved up to 8.1 mW received power at 40 mm depth using a millimeter-scale ME transducer.
• The biphasic AC stimulator demonstrated 6.6 V tolerance with minimal residual electrode voltage.
• Neural signals were recorded and transmitted wirelessly at 186.2 kbps with a bit error rate below 10^-3.

Conclusions:

• The developed MagSonic ASIC is a feasible wireless solution for neural stimulation and recording.
• The integrated design simplifies system complexity and reduces overhead.
• Animal experiments confirmed the potential of ASIC's direct AC stimulation for future neuroprosthetics.