I'm carrying out a research project this year at uni, which will include creating small electronic sensory devices for children (under 7) with autism. Obviously, safety has to be taken very seriously.
Only relatively small amounts of current will be used - probably powering simple sensors on an Arduino board - but seeing as my knowledge of all things electronic is pretty limited, I thought I'd try and get some suggestions first.
From the research I've done, I found PoE at littlebird: http://littlebirdelectronics.com/collections/freetronics/products/4-channel-power-over-ethernet-midspan-injector - which looks like a pretty good solution, seeing as I want the ability to control the device remotely, over a local network. A benefit also being that I can keep the number of wires poking out of the device to a minimum and also not have a direct lead going to a wall socket.
So far, I'm really only at the stage of planning the 'core' of these devices, which would be an Arduino board with limited sensors attached, possibly using the internal parts from a Wii remote. Because I don't yet have confirmed participants, I don't know exactly what sensory needs I'll be working with (each autistic child will have specific sensory issues) and therefore exactly how much power I will need for the devices. I will aim to keep it at a minimum though, simply for safety reasons.