These actuators are 3D-printed from TPU and PLA. Here is a video accompanying the research paper that demonstrates the actuator design. See it in action in two short videos, embedded just below the page break. Stack up a bunch of these actuators, and with careful pressure control, complex movements become possible. This makes a simple actuator bi-stable and capable of different movements, using only a single pressure source. Whether or not this section is popped out changes the actuator’s shape, therefore changing the way it deforms.
This section holds its shape until a certain amount of negative pressure is applied, and the section pops back in. The key is a modified design based on the Kresling pattern, with each actuator having a specially-designed section (the colored triangles in the image above) that are designed to pop out under a certain amount of positive pressure, and remain stable after it has done so. How is this done? By making the actuators physically bi-stable, in a way that doesn’t require additional sources of pressure. The Kresling pattern, which inspired the actuator design.īut by taking structural inspiration from origami, researchers created 3D-printed actuators that show it is possible to get complex movements from actuators fed by only a single source of pressure. Inflatable actuators that change shape based on injected pressure can be strong, but their big limitation is that they always deform in the same way.