An Inexpensive 3D Printed Periscope-Type Smartphone-Based Spectrophotometer for Emission, Absorption, and Fluorescence Spectrometry

We present the design of a periscope-type VIS spectrometer for educational purposes that combines strong features from various earlier designs and adds new ones. Three 3D-printed pieces that hold a small thin mirror sheet, a 1/8th wedge of a DVD, and two razor blades are easily assembled and facilitate insight into its construction. A new feature is the permanent attachment of the flexible back cover of any smartphone, allowing for repeated removal and insertion of the smartphone with precision alignment for recording spectra. An optional fourth 3D-printed piece acting as a container for a PMMA UV semimicrocuvette, a white LED and a UV LED, and a 9 V battery attaches to the front. Beyond commonly applied absorption spectroscopy with similar devices, our design also allows for fluorescence spectroscopy. We report results of straightforward experiments illustrating the various uses of this less than 40 MiniSpectroscope.