As you know, one of the big things holding back all-electric cars is battery life. Without having an internal combustion engine to aid in recharging the batteries on the fly, straight electric drive vehicles will have limited range.
Some people way smarter than me – Noaman Makki and Remon Pop-Iliev of the University of Ontario Institute of Technology in Oshawa – may have come up with an answer. And it involves piezoelectric technology to turn tires into power generators.
Makki and Pop-Iliev experimented placing piezoceramic benders attached to the innerliner of tires as a means to use the “cyclic deformation of the contact patch to generate energy for onboard electronics.” Notice where their words begin and mine end….smart guys, eh?
Here are some more of their words: “Piezoelectric materials generate electrical energy when subjected to mechanical strain. Power-generation devices based on such materials have surfaced in recent years in the context of vibrational-energy harvesting. However, their output has only been sufficient to power sensors and other small, low-energy-consumption gadgets. Benders made of PZT (lead zirconate titanate, the most common piezoelectric ceramic material) attached to a tire have also been used, but only to supply energy to tire-pressure sensors that operate intermittently. To obtain high-power output from this process, it is imperative to cover as much of a tire’s inner surface area as possible with PZT benders. In this way, and because these elements produce power through deformation at the road-tire interface known as contact patch, a reliable and continuous source of energy for the moving vehicle is guaranteed.”
As you can see by the accompanying photo, a piezoceramic array was placed in some test tires by the scientists and run on a dynamometer. The testing revealed that, “The 4.6 watts generated with PZT benders provide sufficient proof of the feasibility of using our method for running onboard devices. Since PZT elements have limited flexibility, high-deformation areas of the tire such as sidewalls could not be covered. We are currently developing a more flexible polyvinylidene fluoride composite stack for the next set of experiments. We anticipate that more tire area can be covered with this material, increasing power output as a result.”
Roughly translated, the future could hold tires that do far more than deliver comfort, traction and safety. They could be far more integral to propulsion than anyone imagined.
