Vanishing Neural Probes: Chronic Implants on Resorbable Substrates

Travis Massey | 20-FS-008

Project Overview

The supporting substrates of conventional neural probes damage tissue and activate the immune response when implanted, resulting in glial scar formation around the probe. This response leads to signal degradation and loss, limiting the duration of neuronal recording.

This study investigated the feasibility of microfabricating a sensing platform in which the substrate dissolves to leave persistent, micrometer-scale sensing elements. We characterized deposition and release processes critical to the fabrication of these devices, demonstrated the dissolution characteristics of three candidate substrate materials, and developed an electrical and electrochemical model of the probe to inform future design decisions. This work demonstrates the feasibility of a new class of bioelectronic interfaces that will enable higher fidelity and more chronically stable clinical interventions for neurological conditions or injuries.

Mission Impact

This work supports Lawrence Livermore National Laboratory's bioscience and bioengineering core competency by developing next-generation biosensors and capabilities that enable evaluation of tissue and disease models. These probes will be valuable tools in developing rapid detection of, and response to, chemical and biological threats—one of the Laboratory's key mission research challenges. Further, the research and development priority of understanding human neurophysiology requires measurement systems that function in vivo for decades, and gliosis-free implants are necessary for high-fidelity chronic interfaces that will provide necessary clinical solutions for the warfighter and general populace. This technology may also be adapted to non-biosensing applications. For example, we expect that the technology can be applied to monitoring stress or other parameters during development of new materials, supporting the Laboratory's broader materials science research goals.