Toward a distributed free-floating wireless implantable neural recording system.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Electrical Engineering

Background:

• Understanding brain function requires high spatiotemporal resolution neural recording.
• Current methods face limitations in long-term, whole-brain coverage.

Purpose of the Study:

• To present the concept and preliminary design of a distributed free-floating wireless implantable neural recording (FF-WINeR) system.
• To enable long-term single unit activity (SUA) acquisition across the entire brain area.

Main Methods:

• Designed a system with tens to hundreds of untethered, wirelessly operating 1 mm3 neural recording probes.
• Utilized a 3-coil link with a high-Q resonator for wireless power transfer.
• Explored microassembly techniques for 1x1 mm2 silicon dies with integrated coils and electrodes.
• Developed circuit designs for compact active circuitry in a 130 nm CMOS process.

Main Results:

• Achieved wireless power transfer with minimum S21 of -22.22 dB in body medium at 2.8 cm.
• Demonstrated power transfer efficiency (PTE) of 0.76% and power delivered to load (PDL) of 759 μW in body medium.
• Successfully implemented a mock-up FF-WINeR probe integrating microelectronic components.

Conclusions:

• The FF-WINeR system concept offers a promising approach for distributed, long-term neural recording.
• The preliminary design addresses challenges in wireless power and microassembly for neural implants.
• Further development could significantly advance brain-computer interfaces and neuroscience research.