

How to Make Electrically Conductive Dough - peter_d_sherman
http://courseweb.stthomas.edu/apthomas/SquishyCircuits/conductiveDough.htm

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erroneousfunk
I run this activity every Sunday as a volunteer at the Boston Museum of
Science. We used to make our own dough, but this became pretty labor
intensive, and we found that regular Play-doh has only a slightly higher
amount of resistance than the homemade dough, and is actually cheaper when you
buy Play-doh in bulk (the dough recipe here calls for a lot of cream of
tartar, which gets costly).

I've done a lot of development on additional components for this (basically
all in my free time, with my money. I bring them into the Museum and just
train other people on them, and they get incorporated into the Squisy Circuits
kit) -- logic gates, on/off switches, blinky components, resistors, etc. The
sky's really the limit! When the Museum started doing it, people got really
bored easily -- I'd hear from staff and volunteers that it was a really
limited activity and hard to really keep kids engaged with it. I found out
that the people running it didn't exactly know a lot about circuits
themselves, so all it took was a little training, experimenting, and coming up
with activity ideas for it to really take off!

In addition, it's one of the few activities we have there where I'm secretly
teaching the adults more than the children. A lot of adults are too
embarrassed to admit they have no idea how electricity works, so I just
pretend their three year old is really really interested in the difference
between parallel and series circuits -- actually in the hopes that the adults
are the ones absorbing it, and can teach their three year old in a few years
;)

Just all-around one of my favorite activities! My boyfriend gets bored from
listening to me talk about Squishy Circuits constantly, so I'm really glad to
see this show up on HN, and get other people interested in it!

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peter_d_sherman
And you can make a battery entirely out of dough (well, you'll need a few
pieces of metal (e.g., paperclips) to link the battery sections):

[http://courseweb.stthomas.edu/apthomas/SquishyCircuits/PDFs/...](http://courseweb.stthomas.edu/apthomas/SquishyCircuits/PDFs/Squishy%20Battery.pdf)

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agumonkey
Would make an irresistible "Electricity theory for kids" class.

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peter_d_sherman
Agreed! But think about it also from the perspective of someone who lives in a
Third World country who wants to experiment with electronics, but who can't
get access to electronic parts.

I'm not sure how you could create a transistor with it however.

I do know that you can create a diode out of a Razor Blade heated to a high
temperature via a gas flame such that carbon deposits form on its outside, and
a sharpened pencil, where a wire attaches to the carbon on the pencil, then
you move the pencil around to find a spot on the razor blade where it works --
this was the operating mechanism in early Crystal Radio sets.

But if only we could create a transistor easily...

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peter_d_sherman
And here are some circuits made with the Electrically Conductive Dough:

[http://courseweb.stthomas.edu/apthomas/SquishyCircuits/build...](http://courseweb.stthomas.edu/apthomas/SquishyCircuits/buildingCircuits.htm)

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linvin
Wow! This could possibly be used replacement for breadboard+wires for trying
out circuits i.e. almost like you can create PCB on a plastic circuit by using
this instead of copper.

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leni536
How fast it goes bad?

~~~
unimpressive
From the article:

>If stored properly, the dough should keep for several weeks.

