Automotive Smart Memory Materials
Automotive engineers have been experimenting with shape-memory alloys and polymers that are referred to as “smart materials”. They change their shape, strength or stiffness when heat, stress, a magnetic field or electrical voltage is introduced.
A family of materials with an capability to alter a couple of its original properties by the application of any external stimuli, such as anxiety, temperature, moisture, pH, electric and magnetic fields are referred to as smart materials. Smart materials are lifeless materials that assimilate distinct functions such as sensing, actuation, logic and control to adaptively react to alterations in their environment to which they are exposed, in a constructive and mostly recurring way. Thermo-responsive materials such as shape memory alloys or shape memory polymers are smart materials which change their shape with alter in temperature.
General Motors Corp. Research and Development Center have employed “smart” supplies technologies for GM products. These GM smart supplies consist of shape memory alloys and polymers, which can change their shape, strength, and stiffness accompanied by heat and other certain elements. To control of the airflow into the engine, a shape memory alloy-activated louver system will be utilized. This smart material functions to decrease the cooling airflow into the engine compartment and reduces aerodynamic drag. The result is improved aerodynamics and drag reduction and rapid warm-up throughout cold engine commence up. This function and other newly developed auto parts feature a shape memory alloy.
In the new Corvette, a shape memory alloy wire opens the hatch vent whenever the deck lid is opened, using heat from an electrical current in a similar manner to the trunk lights. When activated, the wire contracts and moves a lever arm to open the vent, allowing the trunk lid to close. Once the trunk lid is closed, the electrical current switches off, allowing the wire to cool and return to its normal shape, which closes the vent to maintain cabin temperature. Shape memory alloys also help remove unwanted mass, which can help improve vehicle performance and fuel economy. The wire actuator used on the new Corvette is approximately 1.1 pound (499 grams) lighter than a conventional motorized system.
The shape memory alloy used on the new Corvette represents nearly five years of research and development work on smart materials for which GM has earned 247 patents. GM has many more smart material applications in the pipeline that will bring even more improvements to future vehicles. In addition, the redesigned seventh-generation sports car is the first vehicle to use a General Motors’-developed lightweight shape memory alloy wire in place of a heavier motorized actuator to open and close the hatch vent that releases air from the trunk. This allows the trunk lid to close more easily than on the previous models where trapped air could make the lid harder to close. Considering there are about 200 motorized movable parts on the typical vehicle that could be replaced with lightweight smart materials, GM is looking at significant mass reduction going forward.
These new smart supplies follow a long list of material applications. A few examples contain novel aluminium forming processes that provide enhanced lightweight body panels, polymer nanocomposites that present superior mechanical properties at lower cost, and magnetorheological fluids for improved chassis systems. The properties inherent in shape memory alloys and polymers have the prospective to be game-changers in the automotive advanced materials field, eventually leading to vehicle subsystems that can self-heal in the event of damage, or that can be designed to change colour or appearance.
Automotive engineers have been experimenting with shape-memory alloys and polymers that are referred to as “smart materials.” They “remember” their original shape and can return to it, opening new possibilities for many movable features, such as replacing the electric motors traditionally used to activate car seats, windows and locks. There are numerous applications for the technology in the automotive industry. These smart materials might eventually replace traditional motors and hydraulic devices. Smart materials will help reduce weight, component size and complexity, while improving design flexibility, functionality and reliability. In addition, they are impervious to water, moisture, dust and other elements that can wreak havoc on electric motors.
The most popular shape-memory alloy (SMA) is nickel-titanium, which is also known as Nitinol. Its unique properties were originally discovered 50 years ago by engineers at the U.S. Naval Ordnance Laboratory. Other SMAs include copper-aluminum-nickel, copper-zinc-aluminum and iron-manganese-silicon. General Motors engineers have been working on SMA applications since the mid-1990s. An adaptive interior grab handle that automatically presents itself from a folded position to make for an easier, more intuitive entry into a vehicle. Active vehicle surfaces, such as air dams and louvers that adjust to govern airflow, improving aerodynamics and performance. Hood, door latch and glove box releases that allow more convenient access. Shape-memory alloys will also be used in the engine compartment.
General Motors received a $2.7 million award from the U.S. Department of Energy to build a prototype system that will generate electricity from the waste heat found in automotive exhaust. When you heat up a stretched SMA wire, it shrinks back to its prestretched length, and when it cools back down it becomes less stiff and can revert to the original shape. A loop of this wire could be used to drive an electric generator to charge a battery. In a hybrid system, the electrical energy could be used to charge the battery. In a conventional engine, this could perhaps even replace the alternator without any load on the engine.
The idea of an SMA heat engine has been around for 30 years, but the few devices that have been built were too large and too inefficient to make it worthwhile. Engineers are interested in smart materials because they offer a way to reduce product complexity and reduce weight. From an actuator technology perspective, SMAs provide many compelling advantages to traditional electromechanical or pneumatic actuation, including very compact size, silent operation, and low mass and cost. These advantages allow a new class of smart components that provide interaction with users and enhanced features that were previously too expensive or complex to produce.
In an alternative use-as highly elastic materials employing the pseudo-elastic effect-shape memory alloys can accommodate up to 20 times the strain of typical metals, making them useful for packaging and deployment operations. In the correct applications, SMA can be less expensive, lighter, smaller and quieter (both electrically and acoustically) than traditional motor-solenoid, bimetal, piezo or paraffin actuators. Many vehicle manufacturers and automotive suppliers can benefit from shape-memory alloys and polymers.
Traditionally, vehicle manufacturers use hundreds of cable actuators, small electromagnetic motors and other mechanical devices to adjust mirrors, seats and headrests; operate windows and door locks; raise antennas; and release latches. Many of these components can be replaced with SMAs. Some of these applications involve replacement of existing motors, such as displays, locks and seating controls, as well as automation of previously passive devices, such as latches. Other innovative areas for SMAs in the automotive industry include haptic interfaces, vehicle entry, automated HVAC components, and control of aerodynamics.
A good memory is something that money can’t buy. Although, memory will soon play a key role in the way that many automotive technologies are designed and engineered in the future.
Need our help? Please don’t hesitate to contact us should you need any assistance regarding this subject. We can provide data, forecasts, reports, and advisory services specific to your requirements. Click here and contact us now! We will reply within 48 hours.