Combined 3D printing technologies and material for fabrication of tactile sensors

Abstract

Recently, 3D printing technology has taken the spotlight internationally with the recognition of the importance of the manufacturing industry. Currently, there are many mature 3D printing processes and materials. However, an absence of fabrication capability of smart structures such as sensors and actuators remains. In this research, we present a hybrid manufacturing process including directprint/cure (DPC) and projection-based stereolithography, along with printable materials for stretchable tactile sensors. The suggested DPC system consists of a robotically controlled micro-dispensing head, and a light curing module combined with projection stereolithography (PSL) retrofitted from a commercial projector. The materials developed in this research are based on a photocurable and stretchable liquid resin filled with multi-walled carbon nanotubes (MWNTs); this polymer/nanocomposite exhibits the piezoresistive property used in tactile sensing. We also used another hybrid process to develop a tactile sensor using a commercial machine to build the sensor body while a dispensing system was used to create the sensing elements. We have characterized the fabricated sensors with several experiments to detect the locations where forces are applied to the surfaces of the sensors. It is concluded that the suggested processes and materials are promising in developing accurate and reliable stretchable tactile sensors.