MIT Engineers Develop Soft 3D Shape-Sensing Skin for Gaming and VR

New Shape-Sensing Technology

Engineers at MIT have created a soft, wearable sheet that can sense and track its own three-dimensional shape. This technology utilizes optical fibers embedded within a silicone sheet to detect bending and pressure. The system demonstrated an error rate below half a centimeter in laboratory testing, which is comparable to or better than existing rigid-sensor designs.

How the Sensing Works

The core innovation involves using flexible rubber optical fibers with black-dyed cladding. One side of the fiber is intentionally roughened, causing different amounts of light to be lost depending on the direction of the bend. This allows for bi-directional sensing. Multiple such fibers are arranged in a zig-zag pattern within a silicone sheet, with an LED at one end and a light sensor at the other for each fiber. The combined responses from these fibers enable the system to discern complex shapes and also improve resilience to damage.

Applications and Capabilities

Beyond shape tracking, the fibers also respond to pressure, allowing the sheet to sense external forces. This capability was demonstrated in a physical therapy scenario where pressure on a forearm was detected. Potential applications for this technology include controlling games, enhancing virtual reality experiences, and assisting in physical therapy.

The current prototype uses 14 waveguides, each 160 mm long, arranged in two layers within a 16 x 16 x 0.5 cm silicone sheet. Data collection and 3D shape reconstruction are handled by an external circuit board and an algorithm running in MATLAB, processing data approximately three times per second.

Future Development

While the sensing surface is fully soft, the sheet itself does not stretch. The current fibers are also thicker than ideal for integration into everyday garments. The team optimized the waveguide layout through simulations to achieve effective shape reconstruction.