Bioresorbable silicon electronics for transient spatiotemporal mapping of electrical activity from the cerebral cortex

Abstract

Bioresorbable silicon electronics technology offers unprecedented opportunities to deploy advanced implantable monitoring systems that eliminate risks, cost and discomfort associated with surgical extraction. Applications include post-operative monitoring and transient physiologic recording after percutaneous or minimally invasive placement of vascular, cardiac, orthopedic, neural or other devices. We present an embodiment of these materials in both passive and actively addressed arrays of bioresorbable silicon electrodes with multiplexing capabilities, that record in vivo electrophysiological signals from the cortical surface and the subgaleal space. The devices detect normal physiologic and epileptiform activity, both in acute and chronic recordings. Comparative studies show sensor performance comparable to standard clinical systems and reduced tissue reactivity relative to conventional clinical electrocorticography (ECoG) electrodes. This technology offers general applicability in neural interfaces, with additional potential utility in treatment of disorders where transient monitoring and modulation of physiologic function, implant integrity and tissue recovery or regeneration are required.

Inorganic semiconducting materials for flexible and stretchable electronics

“…In an advanced example, actively multiplexed sensor arrays in thin flexible formats allow mapping of electrical activity on the surface of the brain with spatial and temporal high resolution. 97 Figure 8b (left) shows a representative device that consist of 64 separate sensing electrodes and 24 wires as interfaces to external data acquisition systems. An important benefit of actively multiplexed readout, enabled by Si NM-based transistors at each electrode, is that it greatly reduces the number of wires needed for acquisition, which is particularly important at high channel counts.…”

“…Delay map for the bandpass filtered data of epileptic spike activity (right). Reprinted with permission from Yu et al 97 Copyright 2016 Nature Publishing Group…”

Silicon-Integrated High-Density Electrocortical Interfaces

“…Recent next-generation advances in miniaturized hermetic sealing of silicon integrated circuits, such as multilayer multimaterial coating [187], and encapsulation using liquid crystal polymers (LCPs) [185], are promising developments toward highly miniaturized implantable electronics for chronic clinical use. Furthermore, recent advances in dissolvable flexible electronics [188], [189] offer alternatives to hermetic encapsulation for acute applications without the need for post-use surgical extraction. Fig.…”

Thermal Release Transfer Printing for Stretchable Conformal Bioelectronics

“…As the core of neurophysiologic monitoring, realizing high‐quality signal collection is an important topic in the research of neural electrode arrays. Related researches have indicated that stretchable/flexible neural electrode arrays, with their excellent mechanical and electrical performance, are superior candidates for the next generation of implantable devices 3, 4, 5, 6, 7, 8, 9, 10, 11. The successful development of stretchable/flexible neural electrode arrays hinges on good conformal contact between the array and the tissue, which enables excellent mechanical and electrical properties,3 as well as low‐cost, stable, and high‐throughput manufactural techniques.…”