University of Illinois at Urbana-Champaign (Champaign, IL) chemistry professor Alexander Scheeline is encouraging students to use their cell phones for more than talking or texting. By purchasing around $3 worth of optical components, students can use Scheeline's method to convert their cell phones to a simple spectrometer—an effective educational tool that Scheeline has been promoting in both domestic and international institutions as far away as Vietnam.
For the light source, a simple broadband white LED powered by a 3 V battery does the trick. Single- or double-axis holographic diffraction gratings and small, clear cuvettes to hold a sample are available from scientific-supply companies for pennies each. And finally, the digital camera with an 8 or 10 bit CMOS detector from a cell phone captures the spectrum for analysis. A baseplate printed on card stock shows students where to position the light source, grating, cuvette with sample, and the cell phone to obtain spectral images. Issues encountered such as stray and ambient light allow students to understand both the strengths and shortcomings of spectroscopy measurements. Students can find freely available software online at http://bit.ly/aUTP9z.
Contact Alexander Scheeline at [email protected].
John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.