A new drug injector called "Comfortably Numb" is a cooling device that numbs the skin prior to getting a shot. A team of three engineering students from Rice University, Houston, United States, created the device to ease the pain of an injection.
Comfortably Numb works like an ice pack, which produces a rapid chemical reaction that cools and numbs patients' skin in seconds.
The device consists of a small 3D-printed cylinder with a metal plate at one end. Inside the single-use chamber are two separate compartments containing ammonium nitrate and water.
When the device is activated, the two ingredients mix and an endothermic reaction cools down the metal plate of the Comfortably Numb. When pressed against the skin, the ice cold metal cools the skin and makes it much less susceptible to pain.
The team designed the device to be single-use rather than reusable because cleaning it for each use and refilling is time-consuming and complicated. The device does not have a built-in syringe, which is the next step for the students.