Compact packaging of high-throughput flexible neural multielectrode arrays for In vivo recording

Flexible neural multielectrode arrays (fMEAs) possess a lower Young’s modulus and, compared with rigid electrodes, better conform to brain tissue, offering the potential for long-term in vivo recording of single-neuron spiking activity. However, conventional packaging approaches impose volumetric and weight constraints, especially as the number of electrode filaments and recording channels increases to meet growing demands for neuronal sampling. These limitations can interfere with the natural behavior of implanted subjects. In this study, integration of a multi-channel neural signal amplifier chip with an fMEA reduced the device volume to 10 × 12.66 × 1.6 mm³ and the weight to 0.383 g. A set of fMEAs including 8 microfilaments and 256 channels was fabricated and successfully integrated using this approach. Furthermore, a batch in-situ modification method for electrodes on wafer was proposed and enabled implantation of fMEAs individually in a high-throughput and compact manner. In vivo recording experiments demonstrated the feasibility of small-volume packaging for high-throughput fMEAs. This study provides a solution for high-throughput, multi-week recordings of neuronal activity in small animals.