Flip-chip based packaging for linear ratcheting microactuators enables 3d stacks of moveble microelectrodes for the brain

Abstract

MEMS based movable microelectrodes now offer the exciting possibility of developing a fully autonomous implantable neural prosthetic system. However, critical interconnect and packaging challenges remain. We report here a novel flip-chip based interconnect and packaging approach for the implantable MEMS microelectrodes with complex moving structures on the die. The proposed approach is chip-scale, versatile (applicable to a variety of substrates and dies), scalable (allowing the realization of 3D stacks), and low-cost. We report here successful in vivo testing of this non-hermetically encapsulated flip-chip based package in long-term rodent experiments.