The cuff electrode provides a stable interface with peripheral nerves, which has been widely used in basic research and clinical practice. Currently, the cuff electrodes are limited by the planar processing of microfabrication. This paper presents a novel cuff electrode using high-aspect ratio carbon nanotubes (CNTs) integrated on a flexible biocompatible parylene. The microfabrication process unites the high quality vertical CNTs grown at high temperature with the heat sensitive parylene substrate in a highly controllable manner. The fabricated cuff electrodes have been utilized for extracellular nerve stimulation in rats. The experimental results demonstrate the proposed CNT electrode has a better performance than Pt electrode in nerve stimulation. Moreover, the effect of electrode position and stimulation frequency is demonstrated in this paper. This preliminary data indicates that flexible 3D CNTs cuff electrode provides an excellent platform for functional electrical stimulation.

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Microelectrodes are widely used as a peripheral nerve interface (PNI) to connect the peripheral nerve to a computer for restoration of sensorimotor function and bionic device motion control. Materials used for implantable microelectrode are still facing the challenges from biocompatibility and bio‐fidelity in neural signal recording and nerve stimulating. In this study, we report that carbon multi‐electrode arrays (cMEAs) can be fabricated using carbon ink, micro resin dimethylsiloxane and 3D printing technology and ink for PNI. In vitro cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that the cMEAs have higher charge storage capacity (CSC) and less impedance than conventional platinum (Pt) electrode. In vivo studies using an animal model demonstrated that cMEAs are more effective in stimulating the nerve to elicit muscle contraction and recording compound muscle action potentials (CMAPs) than the Pt electrode. The cMEAs has lower stimulating threshold to elicit muscle activity, higher signal‐to‐noise (SNR) in CMAP. Our studies demonstrate that cMEAs can be an advanced healthcare materials in nerve signal nerve stimulation for PNI and muscle bioelectrical signal recording for peripheral muscle interface (PMI).

A biologically inspired compound eye system is fabricated for the detection of object motion without the need for sophisticated image processing. The array of the artificial optical unit, called ommatidium, structurally and functionally mimics the natural compound eyes for motion detection. Each artificial ommatidium consists of polymer lenses, a light-guiding polymer cone, a 3D printing cladding, and a light intensity sensor to measure the change of light intensity during motion detection. To simplify the signal processing and improve the system reliability, low-cost light sensors, instead of CMOS/CCD arrays, are used for measuring the light intensity changes caused by object movement. The distance and speed of a moving metal ball of a pendulum were measured using the compound eye system. The measured results agree well with the theoretical analyses. The error between the measured and calculated speed is less than 2%.

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