An Arduino Spectrophotometer for Some At-Home Science Fun

Spectrophotometers are scientific instruments that measure how different light wavelengths are absorbed by a sample. They have been integral in the field of biochemistry since their invention in the 1940s. While Daniel Hingston has no real need for such a tool, he decided to build his own as it seemed like an interesting project.

In his 3D-printed device, light is shined on through a small slit via an E10 filament bulb, and on the other side an LDR measures the light intensity. In between the bulb and the sample, a triangular prism breaks up the light into the different colors of the rainbow. This is rotated with a small 9g servo, allowing it to record different intensities individually.

Samples are inserted into the chamber, a switch is flipped to turn on the light, and a button gets things going. The lid is then closed to keep everything otherwise dark inside, and a NeoPixel ring acts as a user interface for the process. The resulting data is sent to a PC over serial, which can later be analyzed in an Excel spreadsheet in order to gain new insights into how a sample behaves under test!