This electronic skin could finally let amputees feel warmth through a prosthetic hand
An amputee's prosthetic hand still cannot feel a coffee cup's warmth or a handshake's grip, but a new electronic skin from Washington State University is closing that gap. The sensor system detects pressure and temperature at a resolution 10 times finer than current commercial glove sensors, according to the researchers behind the project.
The work, led by graduate student Hongyi Shen in WSU's School of Mechanical and Materials Engineering, appears in the journal Cell Reports Physical Science . Shen said the approach could make medical-grade e-skin viable for widespread clinical use rather than a costly niche product reserved for a small number of patients.
Fitting complex limb shapes
Electronic skins already exist commercially, but they tend to be expensive, cover only small areas, and struggle to fit a limb's actual shape . Shen said that tradeoff runs deep: the more these devices get customized to fit a specific shape, the worse their sensing performance tends to become.
The WSU team built sensor modules as thin, layered sandwiches combining pressure and temperature sensing elements, designed to conform to the freeform curves of a real limb. Corresponding author Kaiyan Qiu said the system uses a "scan-model-print" process that scans a prosthetic's geometry, then maps sensors across that exact shape for seamless coverage.
Snapping together like Lego
Rather than relying on adhesives, individual sensor modules snap together mechanically, similar to interlocking building blocks. Qiu said the manufacturing process, built around 3D printing and laser cutting, keeps production relatively simple, low-cost, and convenient to scale.
That modular design lets the sensing array measure both pressure and temperature at high density across flat or curved surfaces alike. Existing e-skins often generate too much sensor data to process in real time. The WSU team designed their system specifically to avoid that bottleneck while maintaining humanlike tactile sensitivity.
Turning touch to signals
Researchers have already filed an invention disclosure for a provisional patent through WSU's Office of Research Innovation and Entrepreneurship. Their next step involves developing an actuator to convert sensor readings into signals that stimulate nearby nerves. That would let an amputee actually feel what their prosthetic hand is touching in real time.
Shen, a trainee in WSU's NRT-LEAD robotics program , said his interest in rehabilitation combined naturally with his background in sensors and 3D printing. He said he hopes the completed device will someday make daily tasks easier for amputees who currently rely on prosthetics without any sense of touch.
The research received partial support through WSU's National Science Foundation Research Traineeship in Next-Generation Robotics, led by professor Prashanta Dutta, also a corresponding author on the study. Additional funding came from Qiu's WSU startup and Cougar Cage funds.
