Researchers at MIT and Tianjin University in China have developed X-Hinges, design software that integrates motion sensors and conductive pathways into objects during 3D printing. Users assemble shapes, including custom geometries, and specify up to three axes of movement; the software embeds sensors at bending points. These sensors convert physical changes, such as bending or compression, into electrical signals that conductive pathways carry to processing electronics.
The system addresses interference that arises when sensors and pathways share the same conductive material, making their electrical responses difficult to distinguish. By assigning different materials to the two components, X-Hinges strengthens sensor signals while minimizing interference from the pathways. Demonstrations include a glove, designed for different hand sizes, that records finger-joint movements and transmits them to a robotic hand for reproduction. It could help robots learn grasping through human demonstrations. Other prototypes include a foldable lamp whose brightness responds to being pinched closed, a tactile device that identifies objects such as a banana, and a shark-shaped game controller with a tail that functions like a joystick when moved vertically.
Calibration remains a challenge: minor variations in the arrangement of electrical components during printing can cause apparently identical objects to generate different readings. The researchers developed a computer vision system to recalibrate sensor outputs and improve consistency across devices, and hope to integrate recalibration into future versions. Building on earlier work on movable printed mechanisms, their longer-term ambition is to combine sensing and actuation in one printing process, enabling objects both to detect interactions and to perform physical actions.
