Biocompatible benzocyclobutene (BCB)-based neural implants with micro-fluidic channel

Biosens Bioelectron. 2004 Sep 15;20(2):404-7. doi: 10.1016/j.bios.2004.02.005.

Abstract

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.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • 3T3 Cells
  • Action Potentials / physiology*
  • Animals
  • Biocompatible Materials / adverse effects
  • Biocompatible Materials / chemistry*
  • Cerebral Cortex / physiology
  • Drug Implants / adverse effects
  • Drug Implants / chemistry*
  • Electric Stimulation / instrumentation*
  • Electric Stimulation / methods
  • Electrodes, Implanted*
  • Equipment Design
  • Equipment Failure Analysis
  • Foreign-Body Reaction / etiology
  • Foreign-Body Reaction / pathology
  • Materials Testing
  • Mice
  • Microelectrodes*
  • Microfluidic Analytical Techniques / instrumentation*
  • Microfluidic Analytical Techniques / methods
  • Neurons / physiology

Substances

  • Biocompatible Materials
  • Drug Implants