Fully-Flexible Multifunctional Polydimethylsiloxane (PDMS) Neural Probe With a U-Turn Polyester Microchannel

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Traditional neural probes often lack flexibility, leading to immune responses and limited functionality.
• Integrating multiple functions like electrophysiology, drug delivery, and optogenetics into a single implantable device remains a challenge.

Purpose of the Study:

• To develop a flexible, implantable neural probe with tunable stiffness and multifunctionality.
• To minimize immune response and enhance tissue compatibility for long-term implantation.
• To enable simultaneous electrophysiology, drug delivery, and optogenetics.

Main Methods:

• Fabrication of a polydimethylsiloxane (PDMS) probe with a polyester-filled microchannel for tunable stiffness.
• Integration of a microfluidic mixer for controlled drug delivery and a μ-LED for optogenetics.
• Mechanical, thermal, and fluid simulations to optimize probe design and ensure biocompatibility.

Main Results:

• The PDMS-polyester probe demonstrated thermally controlled stiffness, softening near body temperature.
• Stable electrophysiological recordings and successful in vitro fluorescence activation were achieved.
• Biocompatibility testing confirmed suitability for long-term implantation with minimal immune response.

Conclusions:

• The developed probe offers a flexible, multifunctional platform for advanced neuroengineering.
• This technology addresses limitations of rigid implants, paving the way for multimodal brain interfacing.
• The probe shows significant potential for reducing tissue response and improving therapeutic outcomes.