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.
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.