Fiber-based sensors are desirable to provide an immersive experience for users in the human−computer interface. We report a hierarchically porous silver nanowire-bacterial cellulose fiber that can be utilized for sensitive detection of both pressure and proximity of human fingers. The conductive fiber was synthesized via continuous wetspinning at a speed of 20 m/min, with a diameter of 53 μm, the electrical conductivity of 1.3 × 10 4 S/cm, a tensile strength of 198 MPa, and elongation strain of 3.0% at break. The fibers were coaxially coated with a 10 μm thick poly(dimethylsiloxane) dielectric elastomer to form the fiber sensor element which is thinner than a human hair. Two of the sensor fibers were laid diagonally, and the capacitance changes between the conductive cores were measured in response to pressure and proximity. In the touch mode, a fiber-based sensor experienced monotonic capacitance increase in the pressure range from 0 to 460 kPa, and a linear response with a high sensitivity of 5.49 kPa −1 was obtained in the low-pressure regime (<0.5 kPa). In touchless mode, the sensor is highly sensitive to objects at a distance of up to 30 cm. Also, the fiber can be easily stitched into garments as comfortable and fashionable sensors to detect heartbeat and vocal pulses. A fiber sensor array is able to serve as a touchless piano to play music and accurately determine the proximity of an object. A 2 × 2 array was further shown for two-and threedimensional location detection of remote objects.

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Fiber electrochemical capacitors show advantages such as light weight and flexibility, and may also be easily integrated or woven into various electronic devices with low cost and high efficiency. In this work, we report the preparation of ZnCo2O4 nanorods on a Ni wire as the fiber electrodes, using a simple and rapid single-step hydrothermal process. The electrochemical properties of the free-standing supercapacitor were analyzed using a two electrode system. The supercapacitor achieved a specific capacitance of 10.9 F g(-1). An energy density of 76 mWh kg(-1) and a power density of up to 1.9 W kg(-1) were also obtained for the fiber supercapacitors. The flexible supercapacitor exhibited remarkable electrochemical stability when subjected to bending at various angles, illustrating the promise for use as electrodes for wearable energy storage.