CNT@leather-based electronic bidirectional pressure sensor

The ability of perceiving external pressures and conducting corresponding signals is one of the important functions of flexible electronics, which has been widely studied in electronic skin, prosthetics, robotics, healthcare, human-machine interfaces, etc. Pressure sensor should not be limited to the detection of unidirectional pressure. Here, a leather-based electronic pressure sensor and corresponding arrays with bidirectional sensing capability are demonstrated. The sensor/arrays consisting of two pieces of stacked leather both modified with acidified carbon nanotubes (a-CNTs) can achieve multi-level response to pressure over a broad working range and sense pulling force opposite to pressure. With polyurethane mixed with ferriferrous oxide (Fe₃O₄) powder being applied to their upper surface, the resistive sensor/individual units of arrays can also detect the magnetic field because of the contactless pulling force generated by the magnetized Fe₃O₄. Being able to sense pressure, pulling force and magnetic field, the leather-based electronic bidirectional pressure sensor and corresponding arrays with good performance not only exhibit potential for mass production and their broad application prospects, but also provide a new insight for the development of flexible electronics.