Multifunctional Composites for Vehicles

According to the U.S. Department of Energy’s Vehicle Technologies Office, a 10% reduction in vehicle weight can result in a 6% to 8% fuel-economy improvement. Replacing cast iron and traditional steel components with lightweight polymer composites can directly reduce the weight of a vehicle’s body and chassis by up to 50% and therefore reduce fuel consumption. Lightweighting in vehicle structures represents a significant opportunity for energy savings on a life cycle basis, however, quality control in the manufacture composite materials is more difficult than with metals and therefore require the development of methods for non-destructive evaluation (NDE) of composite materials are required to ensure they meet design and safety specifications. Furthermore, composite materials have greatly reduced thermal conductivity which can lead to increased stress in bonded joints as well as poor heat removal from components under the hood. Additionally, composite materials exhibit poor electrical conductivity which is required for EMI shielding of electrical components or the dissipation of static electricity. With electric and hybrid vehicles, the EMI issue is magnified by the large magnetic field between the cables of the battery and the engine, as well as the battery and the charger, which can negatively affect other electronic systems in the vehicle. Incoming EMI is also a source of concern as it can harm the battery and its circuits. This SBIR will directly address these challenges through the development of low-cost electrically conductive graphene which can be patterned and applied to either thermosetting polymer such as SMCs or grown directly on the surface of certain thermoplastics to provide functional properties. Our preliminary work has also shown that the graphene treatment can greatly improve fracture toughness which reduces commercialization risk and provides the ultimate multifunctional solution, one that increases strength while simultaneously embedding additional functionality. This SBIR will specifically investigate the use of graphene for embedded strain sensing and EMI shielding in composite materials. We will work with OEMs and Tier 1 suppliers to guide our focus towards commercialization and ensure we attack relevant problems and implement scalable manufacturing processes. The proposed multifunctional treatment is not limited to vehicle structures and therefore has tremendous commercialization potential and the ability to provide benefits to both government agencies and the public. Ultimately, Trimer’s novel approach provides a combination of properties that has excellent potential to be applied across the automotive industry as well as in a broader range of commercial composite applications. The global automotive composites market was approximately $7 billion in 2017 and is estimated to nearly double to $13 billion by 2022. Lightweighting of vehicle structures represents a significant commercial market and opportunity for energy savings, and also provides an opportunity to incorporate functional materials due to the multiphase nature of the composites. With autonomous vehicles on the horizon, the need for embedded sensing and EMI shielding is growing and will constitute an important piece of the automotive composites industry. Low-cost automotive composites that utilize LIG coatings to produce embedded sensors, electrical interconnects and EMI shielding as well as improved thermal conductivity will provide a step-change in vehicle energy efficiency, particularly for electric and autonomous vehicles. The compatibility of the process with existing thermoplastics and prepreg materials will allow Trimer to effectively market the multifunctional composites without the requirement for costly capital equipment and will furthermore allow automotive manufacturers to maintain their existing supply chain.