Heat-activated “smart material” debuts in 2014 Corvette
The rear of the 2014 Chevrolet Corvette, which will feature GM's first use of "smart materials"
Chevrolet is taking some major steps to improve and evolve the Corvette – the automaker is bringing back the beloved Stingray and adding a 6.2L V-8 LT1 engine with over 450 horsepower (335kw). Now, Chevy has revealed its intentions to incorporate heat-activated "smart materials" into the 2014 Corvette.
Chevy and GM are starting small, using a shape memory alloy wire that opens the hatch vent whenever the deck lid is opened in the rear of the car. Basically, heat from an electrical current activates the small wire, which moves a lever arm to open the vent, allowing the trunk lid to close. Once closed, the current switches off, and returns to its original shape.
This replaces a conventional motorized system that weighs approximately 1.1 pounds (499 grams) more.
While it sounds like a small change to the overall weight of the car, Chevy points out that "there are about 200 motorized movable parts on the typical vehicle that could be replaced with lightweight smart materials." A pound here and a pound there can add up to some serious weight reduction, which can improve performance and fuel economy going forward.
Shape memory alloys are typically made of copper-aluminum-nickel or nickel-titanium, and are able to change their properties when activated by heat, stress, a magnetic field, or electrical voltage. Once deactivated, they return to their original shape. It's easy to imagine other places where these materials could replace larger, heavier components.
GM has big plans for these smart materials in the future. The company reportedly has "many more smart material applications in the pipeline that will bring even more improvements to our vehicles going forward.”
About the Author
Dave is an avid follower of all things mobile, gaming, and any kind of new technology he can get his hands on. Ever since he first played an NES as a child, he's been an absolute tech and gaming junkie.
All articles by Dave LeClair
Er, why on earth does a sportscar need an electric, or otherwise automated, means of opening the rear hatch in the first place? Are Americans too lazy even to open the trunks of their cars?
Ok, I can see the point of a self-opening trunk lid on something much larger, such as a station wagon, where the owner might be approaching with an armful of groceries, but perhaps the need to automate everything (and build it down to a price) is partly why American sportscars are so derided in Europe?
Would also help its cause if it had been styled, rather than using a cut-and-paste mashup- sportscars are supposed to be beautiful and graceful. This one just looks tacky and derivitive.
If you read it again, the vent is there to allow you to close the trunk.... Ie the doors and other areas are sealed so tightly that there needs to be a place to displace the air when closing one of the openings to the outside world.
Good attention to detail
The vent is necessary both to relieve the vacuum produced by raising the hatch cover which is well sealed to prevent rain entry and to vent the air pressure produced on closing. A little forethought would prevent sophomoric criticism. This is a well engineered vehicle, not subject to arbitrary design features.
@bergamot69, the device they describe in the article doesn't open the hatch. It opens a vent in the body below, which allows the deck lid to close more easily. If you look at the picture, you can see a 3D diagram showing where the vent is, that gets opened by the memory wire.
The reason for this is this: When you try to shut a hatch, it causes an increase in pressure inside the passenger compartment. If there is no way to vent air to equalize the pressure, you have to slam the hatch, which is potentially damaging to an all-glass hatch. This also prevents uncomfortable pressure changes in the ears of a passenger, who might be in the car.
My dad had an '86 Z-28 that had an all-glass hatch. It had a motorized pull down mechanism on the glass for this reason. Once the latch reached the mechanism, the motor pulled the hatch down the rest of the way, slowly, to seal the hatch.
@bergamont69 - Actually in some areas we are lazy, in other areas we are just damn innovative. The one thing I have to ask you is how lazy it is to write a comment blasting us while not even understanding the article and how it is being implemented on the vette? As stated in the article, it will be used "in place of a heavier motorized part to open a vent that allows the trunk lid to close more easily." Do you know what a vent is? (I know cars are smaller in Europe but a hatchback is a little bigger than a vent) Do you understand how the internal pressure of a small cabin can affect one's ability to close a door/trunk and to seal it shut? Notice in any cars how the window drops down a bit when you open the door and goes up a bit to close the window when you shut the door? That is what this innovation is addressing. God, I hate intellectual laziness and how it is replaced with cynicism.
A link to your beloved European design and how they address this phenomenon:
I wonder why they are using an electric actuator, wouldn’t 2 spring loaded pop off valves work (one for opening & one for closing the hatch)?
It is rather absurd to use the word smart in connection with a car that makes at least three times the needed power, has poor ground clearance and has an awful record of theft as well as fatal injuries in a wreck. In short Corvettes are about like a Chevy Vega, poorly designed cars that should never have been on the roads.
Pop-off valves would "Pop" which is what this is the solution for. Relieving the pressure and not requiring it to relieve itself seems logical. A Nitinol solution if applied to greater degree is a solution looking for myriad problems to solve. I'm amazed at the European influence on the Vette. I have never thought of the Vette as a sports car but rather a Muscle car. Pop a V-12 in that baby and Go Man Go!
I was thinking the same thing. In fact my Prius has something very like that. It's a simple rubber flapper valve on the bottom passenger side of the underdeck storage area- below the battery. (The 12V lead-acid battery, not the NiMH Hybrid system battery pack- which is under the rear seat.) I'm guessing that my Nissan Quest has something similar, but I don't know where that one is located. So why does the 'Vette need a device that is in any way powered to perform this function? Just another part to malfunction.
I would have thought that the climate control system would provide the necessary venting.
I've seen alot of great tech comming from the Corvette race team and after awhile other companies hyping up what they adopted as if it were their own. While this Memory shape alloy is only a small part of the vehicle, in time I see it will have bigger applications. Sure enough, other car companies will come in and use it as if it were their own design again and mark up the prices of their cars again. Buy American We make original and we make it well..
bergamot69: how many electric motors are in your beloved Euro sports cars, running all sorts of apparatus to compensate for all manner of issues brought forth by refinement engineering. I'm rather happy the US is able to dilute the pool of places to spend 100K or so on sports cars.
Over 160,000 people receive our email newsletter
See the stories that matter in your inbox every morning