Researchers have developed a new type of tactile sensor using additive manufacturing.
The team at the Seoul National University of Science and Technology developed auxetic mechanical metamaterials that could be used as pressure sensors. A metamaterial is a 3D design that provides mechanical properties different than those present in the base material.
“Auxetic” means that the mechanical forces are inward, and that’s precisely what’s happening when the voids are collapsed under pressure, as seen in the image at the top.
The 3D printed sensor includes spherical voids that are filled with air. When pressure is applied, the voids collapse inward, and this lowers the effective dielectric constant between the electrodes.
There are some advantages to this approach. The design provides for better sensitivity than conventional designs, is stable over more than 3000 pressure cycles, and is thermally stable up to 60°C. They also found that performance could be controlled through changes in porosity.
The samples made by the researchers were produced using resin 3D printing, specifically with a Carima system. The resin was CUKE05C polyurethane resin from Carima.
The researchers demonstrated the approach through two experiments. One involves a 4 x 4 tactile array that was able to classify different objects. The other was a “smart insole” that contained sensors of this type. This design was able to monitor gait and pronation in the wearer.
Those give you some ideas of how this technology could be adapted for the production of unusual smart products.
The field of metamaterials is still not well explored, as the possibilities are limited only by the geometry you are able to 3D print.
You can print almost any geometry with 3D print technology.
