3D-Printed Flexible Tactile Sensor Mimicking the Texture and Sensitivity of Human Skin

The development of 3D printing technology toward multifunction devices may affect various fields from intelligent systems and wearable electronic devices to energy storage and flexible light-emitting devices. A new type of piezoresistive sensor is designed by mimicking the texture and sensitivity of human skin. It is fabricated by 3D printing with a new kind of ink that is composed of interconnected polydimethylsiloxane microspheres (MPs) with carbon nanotubes distributed on their surfaces. This structure gives an electronic skin fabricated from these sensors modulus similar to that of human skin; furthermore, it elastically deforms under external forces. The response of the electronic skin to shear forces is evaluated by simulating the touch behavior of human skin, and it is found that the tactile sensors are sensitive to applied shear forces. They demonstrate sensitivity as low as 2.08 kPa(-1) at a pressure of just 0.12 kPa, with short response time (50 ms), high durability (over 8000 cycles), and flexibility.