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Soft sensors that can discriminate shear and normal force could help provide machines the fine control desirable for safe and effective physical interactions with people. A capacitive sensor is made for this purpose, composed of patterned elastomer and containing both fixed and sliding pillars that allow the sensor to deform and buckle, much like skin itself. The sensor differentiates between simultaneously applied normal force and shear using summation and differences of signals from four deformable capacitors. Cross talk from shear to normal force is less than 2.5%, and between shear axes is less than 10%. Normal and shear stress sensitivity is 0.49 kPa and 0.31 kPa respectively, with a minimum displacement resolution of 40 μm. In addition, finger proximity is detectable at a range of up to 15 mm. The operation is demonstrated on a simple gripper holding a cup. The combination of features and the straightforward fabrication method make this sensor a candidate for implementation as a sensing skin for humanoid robotics applications. [ABSTRACT FROM AUTHOR]

A cost-effective approach was applied to prepare hierarchical porous carbons by simple carbonization and NaCl activation of Artemisia argyi rod at different temperatures. The obtained Artemisia argyi rod–based porous carbon (AARC)-700 material possesses high specific surface area of 1141.8 m2 g−1 and has a hierarchical structure with rich micro-, meso-, and macropores. As electrode for supercapacitor, AARC-700 shows an outstanding electrochemical performance of 348.4 F g−1 at 1 A g−1 in 6 M KOH electrolyte and a superior capacitance of 140 F g−1 at 100 A g−1. At a wide voltage window of 2.0 V, the energy density of the assembled symmetric supercapacitor (AARC-700//AARC-700) at a power density of 2.0 kW kg−1 in 1.0 M Na2SO4 aqueous electrolyte is as high as 32.06 Wh kg−1. Even at a high power density of 40 kW kg−1, a high energy density of 16.67 Wh kg−1 can be achieved. Moreover, the symmetric supercapacitor shows capacitance retention of 99.7% after 20,000 continual charge/discharge cycles at a high current density of 5 A g−1. The results indicate that AARC-700 has bright prospect for application as an electrode material for energy storage. [ABSTRACT FROM AUTHOR]