Scientists Make Breakthrough in Prosthetic Technology

Scientists have developed a prosthetic system that enables amputees to experience temperature sensations—specifically warmth and coldness—in their phantom limbs. This innovative approach leverages the phenomenon of phantom limb sensations, where individuals perceive feelings in a limb that has been amputated.​

Phantom limb sensations occur when amputees feel that their missing limb is still present, experiencing sensations such as itching, pressure, or even pain. This phenomenon is believed to result from the brain’s neural map continuing to send signals to the absent limb’s nerves. Approximately 50–80% of amputees report such experiences, which can significantly impact their quality of life. ​

Researchers from the Swiss Federal Institute of Technology Lausanne (EPFL) have developed a non-invasive device that stimulates specific nerve endings on the residual limb to evoke thermal sensations in the phantom limb. The system, known as MiniTouch, consists of a thin, wearable sensor placed on the prosthetic finger, which detects the thermal properties of objects. This information is then transmitted via thermal electrodes (thermodes) to the residual limb’s skin, creating the illusion of temperature changes in the missing hand. ​

In clinical trials involving 27 amputees, 17 participants reported feeling temperature changes in their phantom hands when the MiniTouch device was activated. One participant, Francesca Rossi from Bologna, Italy, described the sensation as “beautiful,” noting that her phantom limb “does not feel phantom anymore because your limb is back.” Another participant, Fabrizio Fidati, emphasized the importance of warmth in social interactions, stating, “Warmth is the most beautiful sensation there is… The integration of these sensations—hot and cold—in my opinion, we need to shake hands (and improve social interactions) with other people… heat is fundamental.” ​

This breakthrough has significant implications for the future of prosthetic development. By restoring thermal sensations, prosthetics can offer a more natural and intuitive user experience, enhancing the emotional connection between amputees and their prosthetic limbs. Professor Silvestro Micera, co-leader of the study, highlighted the social importance of temperature feedback, stating, “Temperature feedback is essential for relaying information that goes beyond touch; it leads to feelings of affection. We are social beings, and warmth is an important part of that.”