Flexible silicon-polymer neural probe rigidified by dissolvable insertion vehicle for high-resolution neural recording with improved duration

This study reports on a novel concept for silicon (Si)-based intracortical neural probes with improved mechanical flexibility and reduced dimensions. Microelectrode arrays with cross-sections as small as 50 × 120 μm2 and polyimide ribbon cables of similar width but a thickness of only 11 μm are assembled into slender, flexible recording systems. As their interfacing section is reduced to the width of the probe shank, the Si-based electrode array can be completely implanted into brain tissue while the cable creates the interface to the external instrumentation. This hybrid probe concept allows the reduction of the implanted volume and probe stiffness by factors of ca. 5 and 1400, respectively, compared to conventional Si probes. As a consequence, the stability of neural recording is expected to be increased. For probe implantation, the probe is stiffened by a bio-dissolvable polymer mold around the probe using the centrifuge-based molding of polyethylene glycol.

[1]  Thomas Stieglitz,et al.  In vitro evaluation of the long-term stability of polyimide as a material for neural implants. , 2010, Biomaterials.

[2]  Patrick Ruther,et al.  Recent Progress in Neural Probes Using Silicon MEMS Technology , 2010 .

[3]  T. Stieglitz,et al.  CMOS-Based High-Density Silicon Microprobe Array for Electronic Depth Control in Neural Recording , 2009, 2009 IEEE 22nd International Conference on Micro Electro Mechanical Systems.

[4]  Diana George,et al.  Removable silicon insertion stiffeners for neural probes using polyethylene glycol as a biodissolvable adhesive , 2012, 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[5]  O. Paul,et al.  Ultrathin Silicon Chips of Arbitrary Shape by Etching Before Grinding , 2011, Journal of Microelectromechanical Systems.

[6]  H. Grubin.  The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[7]  Henrik Jörntell,et al.  Implant Size and Fixation Mode Strongly Influence Tissue Reactions in the CNS , 2011, PloS one.

[8]  Il-Joo Cho,et al.  Partially flexible MEMS neural probe composed of polyimide and sucrose gel for reducing brain damage during and after implantation , 2014 .

[9]  K. Mabuchi,et al.  Parylene flexible neural probes integrated with microfluidic channels. , 2005, Lab on a chip.

[10]  Brian J. Kim,et al.  Novel flexible Parylene neural probe with 3D sheath structure for enhancing tissue integration. , 2013, Lab on a chip.

[11]  O. B. Ozdoganlar,et al.  An ultra-compliant, scalable neural probe with molded biodissolvable delivery vehicle , 2012, 2012 IEEE 25th International Conference on Micro Electro Mechanical Systems (MEMS).

[12]  Patrick Ruther,et al.  Comparative study on the insertion behavior of cerebral microprobes , 2007, 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[13]  P. Dobson.  Physics of Semiconductor Devices (2nd edn) , 1982 .