A team of researchers from the Daegu Gyeongbuk Institute of Science and Technology (DGIST) and Gachon University has designed a low-cost multi-directional pressure sensor that, they say, could find use in future robotic grippers and other tactile sensor systems.
Building on earlier work, which produced 3D-printed pressure sensors capable of working in only a single direction, the team was able to build a version which can work in multiple directions — and which is suitable for printing on an off-the-shelf 3D printer.
The trick: A new printable conductive polymer, based on polylactic acid (PLA) treated with multi-walled carbon nanotubes (MWCNTs). Based on a bumper structure, the sensor — which also employs a commercial elastomer — uses three pressure-sensing elements to detect pressure in multiple directions at once. An added temperature sensor allows for calibration of the measured electrical resistance, which varies with temperature.
"Our multi-axis pressure sensor successfully captures the readings even when tilted forces are applied," says Hoe Joon Kim, assistant professor of robotics at DGIST, of the work. "Moreover, the temperature-sensing component can calibrate the resistance shift with temperature changes. In addition, the scalable and low-cost fabrication process is fully compatible with commercial 3D printers."
"The proposed 3D printing technology has a wide range of applications in energy, biomedicine, and manufacturing. With the incorporation of the proposed sensing elements in robotic grippers and tactile sensors, the detection of multi-directional forces along with temperature could be achieved, heralding the onset of a new age in robotics."
The team's work has been published under closed-access terms in the journal Composites Part B: Engineering.