Self-rectifying magnetoelectric metamaterials for remote neural stimulation and motor function restoration

Area of Science:

• Materials Science
• Biotechnology
• Neuroscience

Background:

• Magnetoelectric materials convert magnetic fields to electric fields for wireless applications.
• Current magnetoelectric materials have resonance frequencies too high for effective neural stimulation.
• Developing methods for precise, low-frequency neural stimulation is crucial for biomedical applications.

Purpose of the Study:

• To design and demonstrate a self-rectifying magnetoelectric metamaterial for precisely timed neural stimulation.
• To overcome the limitations of high resonance frequencies in existing magnetoelectric materials for neural applications.
• To enable wireless, targeted neural stimulation for potential therapeutic interventions.

Main Methods:

• Fabrication of a nonlinear magnetoelectric metamaterial utilizing semiconductor layers.
• Exploitation of nonlinear charge transport to generate a steady bias voltage under alternating magnetic fields.
• Generation of arbitrary pulse sequences with significant time-averaged voltage biases (>2 V).

Main Results:

• The metamaterial successfully generated controllable electrical pulses from magnetic fields.
• Wireless peripheral nerve stimulation was achieved in an anesthetized rat model, restoring a sensory reflex.
• Signal propagation in a severed nerve was restored with latencies under 5 milliseconds.

Conclusions:

• The developed magnetoelectric nonlinear metamaterial offers a viable solution for precise wireless neural stimulation.
• This technology supports advanced applications in biotechnology and electronics, particularly in neural interfacing.
• Rational design of magnetoelectric metamaterials opens new avenues for remote neural modulation and therapeutic strategies.