SBIR Phase I: Liquid Metal-Elastomer Composite for Electromagnetic Shielding

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to provide new methods and materials to improve electromagnetic interference (EMI) and radio frequency (RF) shielding. EMI/RF shielding are critical for protecting electronic devices from electromagnetic disruption, interference, or data theft. The uninterrupted operation of these electronic devices is essential in a wide range of existing and emerging products and applications, from mobile technologies and personal computing to internet of things, smart textiles, and wearable electronics. However, poor mechanical contact and issues with reliable sealing are critical pain points for EMI/RF shielding applications related to these applications. Improved performance depends on materials that are highly deformable and can maintain a low "lack of conformity" between mating surfaces, an acute challenge that has driven commercial demand for softer and more deformable EMI/RF shielding materials. This project will advance the development of a new material. This Small Business Innovation Research (SBIR) Phase I project will develop a materials technology that combines high performance electromagnetic interference (EMI) with extreme elasticity, mechanical compliance, and toughness. This technology is based on a liquid metal embedded elastomer (LMEE) architecture in which droplets of liquid metal are suspended within a soft elastomer matrix. These composites have a unique combination of properties not possible with other elastomers: (i) high electrical conductivity, (ii) high strain limit, (iii) low elastic modulus, and (iv) high fracture toughness. Because of its high electrical conductivity, LMEEs are effective in disrupting electromagnetic waves and RF signals. Furthermore, because of its high elasticity and tear resistance, LMEE can be used for EMI shielding within tubing, hoses, seals, gaskets, and rubber-based packaging as well as in bags, clothing, and other textiles. This project will result in an LMEE composite with adequate conductivity to shield electronic devices from interference over a wide range of frequencies. Moreover, it will be mechanically robust and resistance to the leakage of liquid metal when torn or punctured. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.