Yes, I thought it was clever, too, Rob. I think this is the way forward and a lot of researchers are thinking this way--to use vibrations and other movements or even sounds or heat from vehicle parts to power sensors on the vehicle itself. There is also work to do something similar with thermal energy on airplanes.
Given the developments in energy harvesting solutions, I take it that reliability is not an issue. I would also guess from these developments that using the energy that drives the other devices on the car is not an option here.
This is a perfect application for energy harvesting. With it, the vehicle uses no onboard energy source to power the TPM system, other than the tires themselves. Another great energy harvesting story, Liz.
I had to laugh when I first read your post Nadine because I went bike riding this evening and kept at a pretty good pace, so my first thought was that my rapid heart beat could have provided the mechanical energy for a heart monitor but then I realized you meant the vibration caused by the impact/motion of the runner's feet going up and down with impact.
Your story inspired a new energy-harvesting design, Nancy! I think both ideas--your heartbeat and the impact of your feet--could work, though. And in fact, they are working, as one company called SolePower has made energy-harvesting insoles, and another called Pavagen has made tiles that harvest energy when you step on them. There are also pacemakers that are harvesting energy from the human heartbeat for power. So your instincts are dead on. :)
Thanks for that link, Nancy. Every time I've read one of Liz's articles, I've wondered about using energy harvesting to power a pacemaker or implantable defibrillator. But I never considered that the heart itself would provide the current. Great link.
That's a good idea, Nadine. There is actually a lot of research right now to have devices power themselves through vibration or other methods. I've done some stories about harvesters on airplanes that use thermal energy to power sensors...and also energy harvesters on shock absorbers on cars that use vibration. I think there are a lot of applications for this. Maybe our readers can think of others.
Thanks, Chuck. I'm sure I will have more energy harvesting stories in the future! But you're right, sensors on vehicles are a great application of this. It's kind of a no brainer, and I expect we'll see more of this type of thing in the future.
That definitely seems to be the direction this technology is heading, Chuck. It doesn't seem to make sense to try to power MCUs any other way now, especially with the deman for ultra-low-power electronics.
Going by the confidence that Panasonic and Imec are portraying in regard to their new development, it would only be right to assume that the effectiveness of the energy harvested matches the other mainstream sources of energy or even surpasses them. It would be a great disappointment to raise the hopes of car developers before a great backlash.
While I agree that tires are a noisy environment I also question the assertions about "shocks" in the tire rotation. There is a flexing motion but that does not fit the normal descriptio for a shock wave. In addition I have a concern about the lifespan of anything attached to the tire's inside surface. While it would be a good location for capturing flexural motion it would also be subject to damage from the tire installation and removal operations. But the concept of powering a tire pressure monitor from vehicle motion is a very good idea. The challenge will be the effort of making sure that the receiver on the vehicle is able to communicate with the tires correctly.
Since shock absorbers were mentioned, I've long thought that there lies an ideal, essentially free, source of recovered energy. Because the very purpose of them is to convert mechanical energy into another form - generally heat - as a means of damping motion, it seems a no-brainer.
With current power management and conversion devices, controlled transformation of suspension motion into electrical energy is looking feasible.
Forgive me if I'm repeating myself, dbell5, but did you see this article I wrote: http://www.designnews.com/author.asp?section_id=1386&doc_id=264515
That's the one about the energy-harvesting shock absorbers. Maybe I posted it already in a comment, if shock absorbers already were mentioned, but I am not sure. In any case, you are right that this seems a great place for energy harvesting.
Transfers the control of a large number of motion axes from one numerical control kernel to another within a CNC system, using multiple NCKs, and enables implement control schemes for virtually any type of machine tool.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.