You have just made an electrochemical cell.
Electrochemical means making electricity from chemicals. Slightly acid
or salty water reacts with our two different metals to produce
electricity. A good cell should produce about 1.5 volts, about the same
as a Duracell. We often call the electrochemical cells we buy from the
shop "batteries". A true battery is more than one cell connected to
others to produce a higher voltage.
A car battery is a true battery made up of 6 cells each
producing 2 volts, adding up to a total of 12 volts all together. AA, C
and D size Energizer brand "batteries" are single cells!
You'll notice that these Energizer and EverReady
"batteries" bought from shops can contain a "paste" inside them so that
liquid doesn't slosh around and leak everywhere, unlike the cell we
The so called "batteries" bought from the shop only make
electricity for a while. When they no longer produce electricity we say
they are "flat", even though they haven't changed shape at all!
Saline Cell Toys - SCT's
A Nexus prototype cell developed by Year 10 student
Jared Broad in 1999 used the idea of using two different metals
inserted into salty playdough. Like an Energizer "battery", our Saline
Cell did not contain any liquid to slosh and spill.
Jared could even add food colouring to make the dough
"batteries" look more fun. Below are just a few examples of simple toys
he developed for the 1999 Science fair (Jared was really busy that year
- entering ALIS the
robot, and a clever oscilloscope computer program and circuit
The SCT power supply - two salt dough cells
produce about 3 volts.
The saline cells (salty playdough)
kept this toy going and going and going....
Want to make a Christmas tree with flashing lights
Imagine adding a PICAXE chip...
Nowadays Jared has a degree in Biophysics and
combines Computing, Electronics and Biology expertise...