Automated Reactive Accelerated Aging for Rapid In Vitro Evaluation of Neural Implants Performance

Objective Novel therapeutic applications for neural implants require miniaturized devices. Pilot clinical studies suggest that rapid failure of the miniaturized neural implants in the body presents a major challenge for this type of technology. Miniaturization imposes stricter requirements for reliability of materials and designs. Evaluation of neural implant performance over clinically relevant timescales presents time-and cost-prohibitive challenges for animal models. Approach In vitro reactive accelerated aging (RAA) was developed to expedite durability testing of these devices. RAA simulates an aggressive physiological environment associated with an immune response and implicated in device failure. It uses hydrogen peroxide, which mimics reactive oxygen species (ROS), and high temperature to accelerate chemical reactions that lead to device degradation. RAA accurately simulates the degradation pattern of neural implants observed in vivo , but requires daily maintenance and is prone to variability in performance. Main results This work introduces automated reactive accelerated aging (aRAA) that is compatible with multiplexing. The core of aRAA is electrochemical detection for feedback control of hydrogen peroxide concentration, implemented with simple off-the shelf components. Significance aRAA allows multiple parallel experiments for a high-throughput optimization of reactive aging conditions to more quickly and more rigorously simulate the in vivo environment. aRAA is a cost-effective tool for rapid in vitro evaluation of durability of neural implants, ultimately expediting the development of a new generation of miniaturized devices with long functional lifespans.