A 2 mm × 2 mm battery-free neural interface achieving 72-channel wireless simultaneous recording by dual overlapped on-chip antennas

• A 2 mm × 2 mm battery-free neural interface chip integrates 72 recording channels using dual overlapped on-chip antennas for simultaneous wireless power transfer and high-data-rate backscatter communication. • The chip achieves an 18 Mbps backscatter data rate, enabling real-time transmission of massive multi-channel neural data without a battery. • An orthogonal coding and sampling technique reduces per-channel power consumption and area, facilitating high-density integration. • Fabricated in 65 nm CMOS, the design demonstrates a compact, scalable solution for high-channel-count implantable neural interfaces.