I'll stick my neck out here and say that if someone paid me to do it I could
*** certainly *** produce a device that generated electrical power from
walking.
I have thought about this a fair bit when I was doing a moderate amount of
walking some while ago. Not a normal mode of longer distance locomotion for
me usually (regrettably).

The trouble with Piezo, as Scott has noted, is that the short distances
involved mean that the forces involved must be multiplied in some manner to
undesirably high levels. This can be achieved by having a very high
deceleration somewhere in the system but this is generally not desirable
when
this is a by-product of walking. Ideally you want to deliver the power as
continually as possible across the working "stroke". Users may :-) object to
platform shoes which telescope to the ground at all times as you walk, so
you are limited to doing something in the deceleration phase as the foot
strikes the ground. A degree of "sponginess" may be acceptable but if this
gets too noticeable the user will quite rightly object.

If I wanted to do this quickly and simply to achieve "some" power I would
probably first look at a mechanical sprung system using rare-earth magnets
and a fairly conventional alternator arrangement. This could be built to be
quite thin and would certainly be able to be built into a shoe heel. A shoe
sole would be harder.

End result could probably feel like an xxx-air-sole but the "air" feeling
would be the alternator magnetics. I would imagine that a fair proportion of
a watt could be achieved "easily"

Consider the effort taken to "pump" the hand operated alternator torches
that one cam buy and translate this into more intermittent but higher force
pulses.
While you would not do this, imagine strapping such a torch on a frame on
you shoe so that the lever was operated as you walked.
- Would it work? - of course.
- Would you feel the forces involved? - hardly, if mounted correctly.
- Could this be translated into a much more professional system? - yes.




      Russell McMahon
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From: Dr. Chris Kirtley <kirtley@CUA.EDU>
>With respect, there's a lot of speculation about power generation from
>walking, but there's nothing out there that works.
>
>Even Bayliss mechanical method seems to be giving disappointing results.
>
>I'd love to be corrected, but I get a bit fed up with everyone telling
>me that it's possible when it ain't!

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