Phantom limb sensations have long puzzled both patients and scientists. The mysterious phenomenon occurs when individuals who have lost a limb continue to feel as though it’s still there. These sensations can include pain, itching, movement, or even temperature changes—despite the fact that the limb no longer physically exists.
Now, groundbreaking research is shedding new light on how these phantom feelings can be reawakened and harnessed to improve prosthetics, particularly through the sense of temperature.
In a study that blends cutting-edge technology with our growing understanding of the human nervous system, scientists have successfully recreated thermal sensations in a phantom limb. The project involved stimulating nerve endings in the residual limb of an amputee, resulting in the perception of hot and cold in the limb that was no longer there.
Bringing Temperature Back to the Phantom Limb
At the heart of this remarkable advance is the work of researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL). Solaiman Shokur, a senior scientist and neuroengineer at EPFL, has been exploring the way amputees experience sensations that seem to emanate from their lost limbs. His team’s latest breakthrough has focused on restoring the sense of temperature to phantom limbs—a feat once thought impossible.
A key part of the study involved integrating temperature-altering devices known as “thermodes” into the prosthetic socket worn by an amputee. These thermodes were placed in precise locations on the residual limb, targeting nerve endings that correspond to the missing hand. By gently altering the temperature at these specific spots, the researchers were able to trigger thermal sensations that patients perceived as originating from their phantom hand.
“In a previous study, we have shown the existence of these spots in the majority of amputee patients that we have treated,” explains Shokur.
The discovery of these “thermal spots” laid the foundation for the current research, which goes even further by demonstrating how temperature feedback can enhance prosthetic function.
A Prosthetic That Feels Hot and Cold
One of the study participants, Fabrizio Fidati, was equipped with a modified prosthetic arm that included thermodes. These small devices were linked to sensors that detected temperature changes and conveyed them to specific points on his stump. The outcome was extraordinary: Fidati was able to correctly identify the temperature of bottles grasped by his prosthetic hand with 100% accuracy.
“Warmth is the most beautiful sensation there is,” Fidati remarked to Shokur. “It’s an interesting technology that would serve to improve prosthetics a lot. 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.”
For Fidati, the experience wasn’t just scientific—it was deeply personal. Without temperature feedback, his accuracy at detecting the temperature of objects dropped to about one-third. But with the thermal cues restored, he regained a sense of connection that most people take for granted.
The Phantom Limb Feels Whole Again
One of the more surprising aspects of the research was how participants described the sensations. Shokur had initially expected patients to point to areas on their stump where the temperature changes were being applied. However, what they pointed to instead was their phantom hand—often even indicating specific fingers or parts of the hand where they felt hot or cold.
“Of particular importance is that phantom thermal sensations are perceived by the patient as similar to the thermal sensations experienced by their intact hand,” says Shokur, who co-led the study.
This suggests that the brain is able to interpret temperature signals applied to the stump as coming from the missing limb, seamlessly integrating the experience as if the limb were still there.
For Francesca Rossi, another study participant, the feeling was nothing short of transformative.
“When I touch the stump with my hand, I feel tingling in my missing hand, my phantom hand. But feeling the temperature variation is a different thing, something important… something beautiful,” Rossi shared.
Her words convey a deep emotional resonance. Temperature feedback provided her with a sense of wholeness, making her phantom limb feel real again.
“Temperature feedback is a nice sensation because you feel the limb, the phantom limb, entirely. It does not feel phantom anymore because your limb is back,” she explained.
A New Horizon for Prosthetic Technology
This revolutionary approach to restoring thermal sensations may change the future of prosthetics. For years, engineers and scientists have worked on making artificial limbs lighter, stronger, and more responsive to movement. But there has always been something missing: the ability to feel. Restoring temperature sensations brings prosthetics one step closer to providing a full sensory experience, allowing users to connect with the world in more meaningful ways.
Imagine a prosthetic hand that can feel the warmth of a loved one’s hand or the chill of a glass of cold water. These are the subtle yet vital sensations that enrich human life and create moments of connection. The study at EPFL shows that it is now possible to reintroduce such feelings, even when the physical limb is gone.
What Comes Next?
Shokur and his team believe this technology could be adapted for widespread use in the future. By refining the placement of thermodes and improving the integration of thermal feedback systems into everyday prosthetics, they hope to make this advancement available to many more people who live with limb loss.
The next steps will involve expanding studies to a larger group of amputees and exploring how temperature sensations can be combined with other forms of sensory feedback, such as pressure or texture. Together, these advancements could create prosthetic limbs that feel increasingly natural—restoring not just function, but the full sensory experience of having a hand or arm.
As Francesca Rossi and Fabrizio Fidati have shown, restoring a sense of temperature can offer more than practical benefits; it can provide profound emotional healing. Their experiences underline the importance of developing prosthetic technology that goes beyond mere mechanics, tapping into the deeper human need for connection and sensation.
With continued research and innovation, the dream of truly lifelike prosthetics—capable of both feeling and function—may soon become a reality.
See the story for yourself in the video below: