All-Paper, All-Organic, Cuttable, and Foldable Pressure Sensor with Tuneable Conductivity Polypyrrole

Paper has been extensively accepted as an ideal platform for fabricating low-cost, flexible, and environmentally friendly electronics. However, current paper-based pressure sensors have not fully demonstrated the unique merits of paper, such as cost efficiency, disposability, cuttability, and foldability, mainly because of the limitation of the applied metal electrodes and device configuration. Here, an all-organic, all-paper, cuttable, and foldable pressure sensor is demonstrated for the first time, with the high-conductivity polypyrrole (PPy) printing paper as electrode and the low-conductivity PPy tissue paper as active layer. Hollow and 3D all-paper sensors are realized through fabricating the kirigami or origami structure since the device can be freely cut and folded, presenting a universal strategy promising for flexible device design. The cuttability and foldability of device create a unique 3D perception capability. The devices show high sensitivity (4.8 kPa(-1)at < 5.5 kPa, 1.7 kPa(-1)at 5.5-40 kPa) and wide detection range (up to 40 kPa), providing a capability for full-range detection of human physiological and motion signals. These results open a feasible route to realize hollow and 3D sensors and fully demonstrate the potential of paper sensors for diverse applications to new-generation green electronics and portable electronics.