Cell
phone need charging? Well, look at your nice new T-shirt and suggest let’s get
a charge out of this. Plug it in and you would be able to get back to your
proper function of keeping the twittering classes fully informed. It’s coming
soon in a store near you – not this year, but soon.
Bao
and Li of U of S Carolina have made a great start according to their paper in
Advanced Materials, which was picked up by the BBC (1,2). They have made bits
of a T-shirt into a super capacitor, which can be charged, depleted and
recharged again, again and again…
The
first step is a rather unconventional wash and dry cycle. They cwashed the
cotton with salt water, sodium fluoride not chloride (hard on the hands so wear
gloves) and then went through a very fierce drying cycle. Firstly it was
pre-dried at 120 Celsius and then at ~900 Celsius in an Argon gas stream to
prevent it from vanishing in a puff of smoke. A final rinse in clean water and a
good dry (120C again) and their white cotton was now a nice black piece of
fabric.
No
dyes nor cotton any longer, but activated carbon, all ready to be decorated.
Little manganese dioxide nano-flowers were electrochemically deposited all over
using deposition from a manganese acetate solution. A nice wash and dry and
their new capacitor was all ready to go.
The
fabric is flexible, mechanically stable and the capacity for being a great
super capacitor. You might not want to sweat too much or go out in the rain
without a coat, but those would be a minor disadvantage compared to hours of
longer twittering time that would become available. The cache´ of asking
strangers if they like the nano-floral decoration on your cell phone charger
would be a bonus.
- http://onlinelibrary.wiley.com/doi/10.1002/adma.201200246/full
- http://www.bbc.co.uk/news/technology-18781878
