The Virtu ultrasonic proximity sensor is available in models with analog voltage or current outputs and has a range of 2 to 20 in. The $129 sensor is offered in dual-mount or barrel-style housings.

Gauhati University researchers have created a flexible, low-cost sensor using pencil, paper and graphene, marking a step ...

I recently had to build an infrared close proximity sensor that could tell if something was dropped in a parcel delivery drop box. After some searching, I ended up using a microcontroller and a piece ...