Fair Mouses and other pets

Continuing the discussion from How about a FairPad?:

Does someone else have experiences with the Fair Mouse from NagerIT?

Do you think it would be possible to build a mouse, which uses its movement to generate energy? (I don’t know a lot about electrical engineering, but there was this thing with a magnet moving in a coil, inducing electrical energy, wasn’t there?)


An interesting thought. Some searching gives a few sources for power draw of mice of the modern optical USB variant - 0.5W / 500mW.

Piezoelectric energy harvesting / generation seems to be in the on the order of milliwatts - too small. But consider the humbler mechanical mouse:

(Logitech mouse picture, they are probably not Fair yet)

It may be possible to adapt the roller wheels to generate electricity (readers note: at this point we’ve firmly crossed into thought experiment territory). Human power is more than sufficient magnitude-wise (WP says manual labourer can sustain 75W over the course of a day); so it would be a case of figuring out how it would feel to use.

Fortunately, the internet provides! (If I’d searched for this off the bat I’d have been quicker…)

and so on.

Verdict: possible!

That’s what I meant with the “Sandberg approach”:

The mouse is supplied with electricity by induction over the included mouse mat.
The product is discontinued. It’s less mobile and mobility is the main reason to have a wireless mouse.
I have no experience with wireless mice so I don’t know how often you’d need to change batteries/put it into docking station.
I think as long as energy is cheap things won’t change. (“As long as work is cheap things won’t change”?)

I nearly went to mentioning inductive powering / charging via a special pad, good to know that someone actually did that! I don’t find changing the mouse batteries to be an inconvenience; certainly not something I do with regularity. On the other hand, Sod’s Law says that the batteries will run out at the least convenient time…

@bertieb Thank you for the interesting links and your research! I think I will waste some more thoughts on the various components. Im particularly interested in the approach of using the hand’s warmth in connection with a thermoelectrical component.


AA batteries last at least 6 month, I don’t know about rechargeable ones though.

@both: I guess the aim should be to completely avoid batteries because of their environment hazards, and also to keep moving parts to a minimum because this also limits the lifetime of a product.

Off the top of my head, thermoelettric generation is even less feasible than piezoelectric (I think) due to inefficiencies and the relatively low temperature differences involved. A quick perusal of the ever-knowing Wikipedia seems to confirm this:

Miniature thermocouples have been developed that convert body heat into electricity and generate 40μW at 3V with a 5 degree temperature gradient, while on the other end of the scale, large thermocouples are used in nuclear RTG batteries.

40μW is a factor of 10 000 away from 500mW unfortunately :expressionless: