Biocompatible benzocyclobutene (BCB)-based neural implants with micro-fluidic channel.
Poly-benzocyclobutene (BCB)-based intracortical neural implant was fabricated, in which micro-fluidic channel was embedded to deliver drug solutions. BCB presents several attractive features for chronic applications: flexibility, biocompatibility, desirable chemical and electrical properties, and can be easily manufactured using existing batch micro-fabrication technology. The fabricated implants have single shank with three recording sites (20 microm x 20 microm) and two reserviors (inlet and outlet). The channel had large volume (40 microm width and 10 microm height), and hydrophobic surface to provide a high degree of chemical inertness. All the recording sites were positioned near the end of the shank in order to increase the probability of recording neural signals from a target volume of tissue. In vitro cytotoxicity tests of prototype implants revealed no adverse toxic effects on cultured cells. The implant with a silicon backbone layer of 5-10 microm was robust enough to penetrate rat's pia without buckling, a major drawback of polymer alone. The averaged impedance value at 1 KHz was approximately 1.2 MOmega. Simultaneous recordings of neural signals from barrel cortex of a rat were successfully demonstrated.
Lee
Keekeun
K
Department of Electrical Engineering, Center for Solid State Electronics Research, Arizona State University, Tempe, AZ 85287-5706, USA. keekeun@asu.edu
He
Jiping
J
Clement
Ryan
R
Massia
Stephen
S
Kim
Bruce
B
D016475:3T3 Cells; D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry*; D002540:Cerebral Cortex / Q000502:physiology; D004343:Drug Implants / Q000009:adverse effects / Q000737:chemistry*; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology; D008422:Materials Testing; D051379:Mice; D008839:Microelectrodes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D009474:Neurons / Q000502:physiology
D001672:Biocompatible Materials; D004343:Drug Implants