Given an input of laser light of one wavelength ... they describe how to make a homebrew safety test. All you need is a CD, a few paper cups, a sheet of paper, and an infrared-capable webcam.

The core of the team's findings lies in a new method for integrating electrodes into paper-based test strips. They achieved this through a process called laser-induced pyrolysis of cellulose paper, ...

Inkjets and laser printers don't technically require different paper. You can use a ream of cheap office copy paper and get results that are adequate for most uses. However, the different ...