Magnetic Actuation of Flexible Microelectrode Arrays\nfor Neural Activity Recordings

Abstract

Implantable microelectrodes\nthat can be remotely actuated via external\nfields are promising tools to interface with biological systems at\na high degree of precision. Here, we report the development of flexible\nmagnetic microelectrodes (FMμEs) that can be remotely actuated\nby magnetic fields. The FMμEs consist of flexible microelectrodes\nintegrated with dielectrically encapsulated FeNi (iron–nickel)\nalloy microactuators. Both magnetic torque- and force-driven actuation\nof the FMμEs have been demonstrated. Nanoplatinum-coated FMμEs\nhave been applied for <i>in vivo</i> recordings of neural\nactivities from peripheral nerves and cerebral cortex of mice. Moreover,\nowing to their ultrasmall sizes and mechanical compliance with neural\ntissues, chronically implanted FMμEs elicited greatly reduced\nneuronal cell loss in mouse brain compared to conventional stiff probes.\nThe FMμEs open up a variety of new opportunities for electrically\ninterfacing with biological systems in a controlled and minimally\ninvasive manner.