Experiments on rats indicate that the gadget blocks pain impulses by evaporative cooling.
In the future, pain control might be much more relaxed thanks to a flexible electronic implant. The gadget surrounds nerves with an evaporative cooler and is made from materials that disintegrate in the body.
Bioengineer John Rogers and colleagues report in the July 1 Science that the cooler prevented pain signals from rushing up to the brain after being implanted in rats. Although not yet suitable for human usage, a future version might allow patients to adjust the level of pain treatment they require at any given time, according to Rogers of Northwestern University in Evanston, Illinois.
Low temperatures have been known to paralyze bodily nerves for some time. However, it is difficult to duplicate this phenomenon with an electronic implant. Scientists require something that gently cuddles the tissues because nerves are delicate. Additionally, the body would absorb a perfect implant, eliminating the need for surgical removal.
The team’s device has a soft cuff that wraps around a nerve like a toilet paper on a roll and is made of water-soluble polymers. Small channels run the length of its stretchy body. The process removes heat from the underlying nerve when liquid cooling that is pushed into the channels evaporates. Scientists use a temperature sensor to find the ideal temperature—cold enough to suppress pain but not so cold as to harm the nerve.
The implant was wrapped around a nerve in rats, and the rodents’ reactions to having their paws pricked were observed. The nerve chiller was turned on, allowing researchers to apply pressure up to seven times greater than usual before the animals withdrew their paws. Rogers claims this is a sign that the rats’ senses have been dulled.
Instead of treating chronic pain, he imagines the gadget being used to alleviate post-operative discomfort. The cooler would be attached to patients like an IV line and connected to an external power source. By changing the coolant’s flow rate, they could regulate the amount of pain relief.
Rogers speculates that such a system would provide focused pain relief without the drawbacks of addictive painkillers like opioids.
“If treating pain, cooling would have to go on for a much longer period of time,” says Seward Rutkove, a nerve physiologist at Harvard Medical School who wasn’t involved in the study. Still, he adds, the device is “an interesting proof of concept and should definitely be pursued.”
Parvathy Sukumaran 
