The final modification is the most crucial
and difficult. The image sensor is located behind
a protective glass plate and is connected to the
rest of the electronics by a set of fine wires
around the edge of the sensor. Removal of the
plate requires breaking another glue seam or
shattering the glass and carefully removing any
shards that land on the sensor. To remove shards,
we use a dry cotton swab followed with a cotton
swab soaked in ethyl alcohol to gently remove
as many remaining shards off the sensor as possible
as shown in the comparison images in figures
2(a) and (b). Webcams use a Bayer matrix
[18] of red, green and blue (RGB) filters laid over
the individual CMOS pixels of the sensor to create
colour images. These filters can be removed
with great care [19]; however, we omit this step
in the interests of safety, simplicity and time.
Experiment and simulation
Radioactive decay produces three radiations—
alpha particles, beta particles, and gamma photons
[20]. Many readily available radioactive
sources exist in the consumer market—including
natural ores, older Fiestaware, and Vaseline glass
[21, 22]. We chose a commercially produced,