Ultra-Soft Neural Probe with a Temporary High-Strength U-Section Coating by Picosecond Laser Micromachining

This paper reports an ultra-soft neural probe with a temporary high-strength U-section coating of polyethylene glycol (PEG) for the first time. Its fabrication is compatible with MEMS processes, and an ultrathin U-section coating over the probe’s back and sidewall is precisely formed by spinning and cold laser cutting. With this novel coating, the probe has both minimized cross-sectional area and sufficient mechanical strength for low-invasive penetration into brain. Besides, the remained ultra-soft deformable probe after PEG dissolution is expected to be the next generation of neural implant for chronic recording.