Harvesting energy is in the news, again, as yet another means to save the world from ourselves. We have wind power, wave power and hydro generation as major sources and potential sources of energy -- although the fish environment extremists and the atmosphere environment extremists differ by a dam, or several, on hydroelectricity. But we're also seeing other smaller programs being developed.
A good example of the latter are the energy harvesting
modules, EH300/301, from Advanced Linear Devices (ALD). They provide the ability to harvest just about any spare energy around -- at low and high voltages, ac and dc -- whether that energy is continuous or intermittent, and not even a straightforward electrical source.
We are also hearing about developments of tiny fuel cells and nano generators using water squeezed through tiny channels. There are projects to recover energy from the vibration of bridges, or passing traffic. There are even generators that can use the strikes of a human heel to develop power. This is, as you might guess, a
defense project and they are now up to a 3 W - 4 W level, per heel.
But an
announcement from the UK that is even smaller caught my eye -- at least today. Researchers at Southampton University (in Hampshire) have been working on a generator that operates on the resonance of its surroundings, although it is being commonly described as a vibration generator. It is a super version of the autowind watch that was so popular in the 1970s.
The particular resonance in this case is the activity around and by the human heart within its cavity. Each generator can be individually tuned for different human behaviors.
Originally designed by the team (led by Reader in Electronics Steve Beeby) for industrial locations within machines, it has now pared down the size of the design for the human environment. High efficiencies are claimed but power output is still very low. The team has now spun off the usual let's-take-financial-advantage-of-work-paid-for-by-somebody-else company, in the form of Perpetuum.
It seems like a nice dream. Maybe, one day, especially as products reduce again and again in size, we will be able to put our iPod (fitted out with one of the generators) in our breast pocket and have it recharge there. When the power goes up maybe it will be possible to grow the consumer product size up to a cell phone?
But Perpetuum’s business model has a teeny-weeny flaw…
The business purpose of the company is declared to be looking at powering pacemakers with the generators. A noble cause, saving patients surgery every couple of years to replace the battery in their lifesaver.
I really hate to be a wet blanket, but someone – or perhaps all of them – does not understand how a pacemaker operates.
"A pacemaker is a small, lightweight, electronic device that's placed inside your body. The pacemaker keeps track of your heartbeat and, when necessary, generates electrical signals similar to the heart's natural signals. These signals keep your heart beating at the right pace.
"A pacemaker helps keep your heart from beating too slowly, but it doesn't stop your heart from beating on its own. The pacemaker "listens" to your heart. When the heart's own electrical system sends a signal and the heart beats, the pacemaker waits and does nothing. When the heart's system misses a signal, the pacemaker sends a signal to replace it."
But, of course, when "the heart's system misses a signal" there is no power coming from the generator -- and no signal from the pacemaker to restart the heart…
Oops!
