MIT and Tianjin University researchers have built X-Hinges, design software that embeds sensors in 3D printed objects so lamps, gloves and toys can sense how they bend.
The tool comes from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and Tianjin University (TJU) in China. It tackles a known problem with printed sensing. Sensors and the traces that connect them were usually printed from the same conductive material. Both then send similar signals, so a device struggles to tell real motion from noise.
X-Hinges splits that job between two filaments. One is chosen for the sensors and sends the strongest possible signal. The other carries the wire-like traces without interfering. The software places both automatically once the design is done.
Users build an object by picking and connecting shapes, then choosing how each part should move. The shape options are a cylinder, a rectangle, a thin outline and a custom form. Each hinge can move along up to three axes. It can compress, bend up and down, or bend sideways. The software then puts sensors where the object bends and records every direction at the same time.
“Most methods only allow for one axis of motion, often due to signal interference,” said Xiang Chang, the paper’s lead author and a TJU PhD student visiting CSAIL. “X-Hinges enables your 3D-printed item to move from three angles.”
The team built several demos. A glove adjusts to the wearer’s hand and records how the finger joints bend. It relays that motion to a humanoid robot hand, which mimics the grasp to learn how to pick up blocks. That could help robots in factories or homes learn new tasks quickly.
An origami-style lamp looks like folded paper until it opens up. Pinching it closed changes its brightness. A sensing platform recognizes objects placed on top, such as a banana, from tactile data alone. A game controller shaped like a cartoon shark uses its tail as a joystick.
“It’s kind of like adding a conscious element to everyday objects,” said Jiaji Li, a senior author and an MIT electrical engineering and computer science (EECS) postdoc at CSAIL. “What you get is objects that better understand how they’re being used and have more ways to respond.”
Calibration is still a bottleneck. The layout of conductive elements varies slightly from print to print. Two parts that look identical can give different sensor readings. Chang and Li built a computer vision system that recalibrates the outputs so matching prints agree. Later they want a recalibration mechanism built into the printed object itself.
Li previously printed tendon-driven mechanisms that let objects move. X-Hinges adds the sensing side. His next goal is to combine actuation and sensing in a single print.
Chang and Li wrote the paper with Stefanie Mueller, an MIT associate professor of EECS and CSAIL principal investigator, and recent TJU graduate Haiyang Yan. They will present the work at the Association for Computing Machinery (ACM) Symposium on User Interface Software and Technology in early November.
Source: MIT News
