Implantable Soft Neural Electrodes of Liquid Metals for Deep Brain Stimulation

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Conventional solid-metal electrodes for neural stimulation cause brain damage due to mechanical mismatch.
• Effective modulation of brain circuits requires advanced electrode technology.
• Liquid metals offer a promising alternative with their low modulus and biocompatibility.

Purpose of the Study:

• To develop and evaluate novel, soft macroelectrodes using biocompatible liquid metals for neural stimulation and recording.
• To address the limitations of stiff conventional electrodes in brain interventions.
• To demonstrate the potential of these new electrodes for therapeutic applications like pain alleviation.

Main Methods:

• Fabrication of implantable soft macroelectrodes by filling polymeric tubes with biocompatible liquid metals.
• Enhancement of electrode tips with platinum nanoclusters to achieve low impedance and prevent leakage.
• In vivo testing in neuropathic pain rat models for simultaneous neural stimulation and recording.

Main Results:

• The liquid metal macroelectrodes demonstrated tissue-like stiffness and stability during in vivo experiments.
• Platinum nanocluster enhancement resulted in low impedance and effective charge injection.
• The probes successfully enabled simultaneous neural stimulation and recording in a pain model.

Conclusions:

• Implantable soft macroelectrodes made from liquid metals offer a safe and effective alternative to conventional electrodes for brain stimulation and recording.
• These novel probes show significant potential for therapeutic applications, including pain alleviation and behavioral control.
• The straightforward fabrication method allows for customization and broad applicability in neural interfacing.