This thesis presents a MEMS actuator capable of extruding or pulling itself along a sub-10μm diameter carbon fiber. The compact silicon microfabricated MEMS actuator can extrude fibers over many millimeters of distance with micron-level precision and is powered externally via high-voltage control signals.
One specific application demonstrated in this work is the insertion of microelectrodes for cortical neural recording. Microwire and microelectrode arrays used for cortical neural recording typically consist of tens to hundreds of recording sites, but often only a fraction of these sites are in close enough proximity to firing neurons to record single-unit activity. The device is shown to precisely insert a carbon fiber recording electrode to a controllable depth into an agar brain phantom. The device is also capable of recording an artificial neural signal in saline. This technique provides a platform generalizable to many microwire-style recording electrodes which elicit minimal to no adverse biological response.
This ‘extrusion and pulling’ capability may enable microrobots to create the surface on which they move, by carrying around filament and extruding it to form arbitrary shapes with micron-level resolution. Initial work is demonstrated towards the realization of a silicon microrobot which can climb or inch along a pre-existing ‘tightrope’ strut. The final sections of this workdiscuss the high-level vision and assembly steps needed to integrate MEMS actuators with other MEMS and circuit (CMOS, etc) payloads to realize a fully autonomous inchworm robot that can carry, arbitrarily form, and crawl along its own tether.