Known as the PlaDeo (as in, plasma deodorant), the gadget was invented by doctors TaeHo Lim and JungChi Seo at South Korea's Hanyang University. An earlier version, called the Pragant, won an Innovation Award at CES 2020. [...] Twice each day, the user starts by holding the PlaDeo gently beneath each clean, dry armpit. A silicone gasket creates a 1-cm (0.4-in) gap between the device's main body and the underarm skin. Pressing and holding the power button causes the PlaDeo to start producing ionized gas (namely cold atmospheric plasma) for 1.5 minutes.  

— Read more in Electronic armpit device uses plasma to make deodorant obsolete at New Atlas.