The novel coronavirus can spread through surface contamination, that means if you touch a surface that has the virus and then touch your eyes, nose or mouth you can get infected. Hence, apart from wearing a mask outside and frequently washing our hands, health authorities have also prescribed people to keep our hands away from the face.
As it is quite difficult to do so in practice, a small team from NASA's Jet Propulsion Lab (JPL) has a pendant made. Known as PULSE, it is a 3-dimensional pendant "that pulses, or vibrates, when a person's hand is nearing their face".
A video clip on how the pendant functions have been uploaded on YouTube. As soon as you wear the pendant and reach for any part above the necklace, you will experience "haptic feedback from a vibration motor", simulating a nudge in your hands. This will readily remind you to keep your hands off of your face.
The video adds that the pendant works most efficiently when worn 6 inches below the chin. Another important point to remember is that the pendant is only an add on device and is not meant to replace masks or respirators.
The official page of the PULSE pendant states that its "simple and affordable" technology can be easily replicated by individuals and companies so that it gets widely distributed.
A list of parts, STL files, and assembly instructions have been made available for the public by JPL as open source. Anyone with a soldering tool, 3D printer, wires, coin battery, and a motor will be able to build the device.