To help address this deficiency, we developed a simple,
rugged, and low-cost homemade visible spectrophotometer. The
homemade spectrophotometer could be constructed by high
school students in physics or chemistry classes using readily
available components. The total cost of the homemade
spectrophotometer is about $25, an eighth of the cost of a
similar device4 and significantly less than commercial units. The
design uses a battery pack, a white light emitting diode (LED)
with current-limiting resistor (similar to those in LED
flashlights), a lens, a cuvette and cuvette holder, a grating
mounted on a slide, a photodiode mounted on a rotatable arm
using a simple steel hinge, and a digital multimeter. For ease of
alignment and use, we made an “optical table” using half of a 10
in. x 10 in. LEGO baseplate and LEGO construction blocks. It
is exciting for students to perform scientific experiments with
familiar materials typically thought of as toys.5 We note that the
University of WisconsinMadison Materials Research Science
and Engineering Center has published many exciting and
educational experiments on “Exploring the Nanoworld with
LEGO Bricks”.5 A photo of our homemade spectrophotometer
is shown in Figure 1.