An implantable, wireless, battery-free system for tactile pressure sensing

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Restoring hand function after amputation or paralysis is crucial for quality of life.
• Wearable tactile sensors are limited for direct neuroprosthetic integration.
• Existing solutions do not adequately provide naturalistic sensory feedback.

Purpose of the Study:

• To develop and validate an implantable tactile sensing system for subdermal placement.
• To create a miniature sensor capable of providing high-resolution tactile feedback for neuroprosthetic applications.
• To establish foundational capabilities for future implantable sensing systems.

Main Methods:

• Microfabrication of a capacitive pressure sensor.
• Development of a custom integrated circuit for wireless power and data transmission.
• Hermetic silica packaging using laser fusion and validation through simulations, benchtop tests, and primate hand testing.

Main Results:

• The implantable sensor accurately measured applied skin forces with a resolution of 4.3 mN.
• The system demonstrated successful integration and data transmission.
• The sensor's output was shown to be suitable for encoding tactile feedback via brain microstimulation.

Conclusions:

• A novel implantable tactile sensing system was successfully developed and validated.
• This technology offers a pathway for restoring naturalistic touch sensation in neuroprosthetic hands.
• The materials, design, and fabrication methods advance implantable sensing capabilities for diverse applications.