A pneumatic neural probe structure fabricated by parylene thermal bonding technique

This study demonstrates a novel pneumatic harden technique to enable the stiffness change of flexible neural probe structure. The probe structure is fabricated by using the parylene thermal bonding process. The merits of this pneumatic-hardening hollow-structure are as follows: (1) using the pneumatic hardening mechanism, this probe structure can easily tune its stiffness by varying the inlet air; (2) pneumatic hardening is a reversible process, and the hardening time can be arbitrarily manipulated; (3) by applying the parylene as the flexible structural material, high bio-compatibility and flexibility can both be achieved. Preliminary results show the critical buckling load can increase from 0.36gw to 0.65gw after inflating. The rat brain insertion using the air-inflated pneumatic neural probe is also demonstrated.