A modular micromachined high-density connector system for biomedical applications.

Area of Science:

• Biomedical Engineering
• Microsystems Technology
• Implantable Devices

Background:

• Biomedical applications require high-density, reliable, and minimally invasive connection systems.
• Existing connectors often face challenges with size, profile, and long-term stability in vivo.
• Micromachining offers potential for miniaturized and high-performance interconnect solutions.

Purpose of the Study:

• To develop and characterize a high-density, modular, low-profile, and removable connector system using micromachining.
• To enable stable and reliable electrical connections for in vitro and in vivo biomedical applications.
• To demonstrate the system's capability for simultaneous biopotential recordings.

Main Methods:

• Fabrication of a connector system using silicon/polyimide electrodes, a titanium base, and a glass substrate with a polyimide diaphragm.
• Integration of high-density gold electroplated pads (32 sites) on the diaphragm and electrode back-end.
• Utilizing a vacuum-actuated mechanism for establishing electrical contact between pads.
• Conducting in vitro electrical tests (contact resistance, crosstalk) and in vivo biopotential recordings.

Main Results:

• Demonstrated low contact resistance (< 5 omega) and stable performance over 70 connections in vitro.
• Achieved low crosstalk (-55 dB at 1 kHz) between adjacent channels.
• Successfully established multiple contacts and recorded simultaneous biopotentials from the guinea pig occipital cortex in vivo.

Conclusions:

• The developed micromachined connector system is suitable for high-density, reliable electrical connections in biomedical applications.
• The modular, low-profile, and removable design facilitates versatile use in various experimental setups.
• The system's performance in both in vitro and in vivo tests validates its potential for advanced neurophysiological monitoring.