If you’ve ever had surgery, you are no doubt familiar with the pain that can follow.

You might be prescribed opioids or other medications, but many patients are leery of taking them for too long, for fear of becoming addicted.

A team led by Northwestern University scientists believes they’ve got a new way to relieve pain that can be targeted precisely and requires no drugs. So far, they’ve shown it works in laboratory rats.

They’ve created a tiny device — the implant they used in the rats was just 5 millimeters wide and no thicker than a sheet of paper — to soothe throbbing nerves. Here’s how it works: Surgeons would implant the device during procedures known to leave patients in pain, and in parts of the body where neural signals are isolated. One end of the flexible, water-soluble cuff wraps around a single nerve, so no sutures are needed.

The cuff delivers the goods through microfluidic channels. One contains a liquid coolant approved for human use as an ultrasound contrast agent and in pressurized inhalers. The other channel contains dry nitrogen. As the two flow into a single chamber, a cooling sensation soothes the angry nerve. A sensor ensures that nerve tissue isn’t damaged by the cold, and the patient can bump up or down the pain relief as needed.

Eventually, the body absorbs the device, as it would dissolving stitches. The study found the materials dissolve in 20 days and any residues are eliminated after 50 days.

Think of it as a high-tech “icing” of an injury — without the annoyance of a thawing, messy ice pack that needs constant attending and won’t stay put. Or just think of it how the researchers described it: cooling away the pain.