A Carbon Flower Based Flexible Pressure Sensor Made from Large-Area Coating

Flexible pressure sensors are an essential part of robotic skin for human–machine interfaces, wearables, and implantable biomedical devices. However, the desirable characteristics of high sensitivity, conformability, and good scalability are often mutually exclusive. Here, a highly sensitive and flexible pressure sensor that can be easily fabricated by coating a carbon flower and elastomer composite is presented. The composite made from uniform-sized carbon flower particles exhibits a contact-based mechanism for pressure sensing, as opposed to typical carbon black pressure sensitive composites which utilize percolation as the sensing mechanism. The contact mechanism allows for an active layer down to 13 µm, and a bending insensitivity down to a 5.5 mm bending radius, while maintaining a high sensitivity. Furthermore, the composite is printed over a large 1 m × 2 cm pressure sensing area, showing the preparation of this sensor can be scaled to large area.