SBIR Phase I: Injection-molded Thermoset Shape-memory Polymers with Enhanced Acoustic Properties

This Small Business Innovation Research Phase I project aims to develop a new material and methodology to design comfortable, custom earpieces based on shape-memory polymers. These devices are stand alone earplugs or attachments to products in three other markets - headphones, hands-free and Bluetooth devices, and hearing aids: any aural device that demands comfort and seal. The work focuses on these adaptive self-adjusting materials that conform to complex contours of the inner ear canal, are comfortable and seal well. The intellectual merit of the project is related to developing adaptive earpieces from tailored shape-memory polymers with enhanced acoustic properties. Current material solutions suffer from several drawbacks, including an inability to control the force exerted by the earpiece upon the sensitive regions of the inner ear and concurrently block out unwanted noise. This Phase I project will develop next generation self-adjusting shape-memory polymers that deliver both long term comfort and an effective seal as cost-effective one-size-fits-all devices. This project will also provide overall proof of concept for enhanced devices and generate a fundamental research knowledge base necessary to ultimately produce successful commercial devices. Due to their desirable properties, chemically crosslinked shape-memory polymers are increasingly being proposed in biomedical applications, but their broader adoption into mass markets has been limited. The novel manufacturing process, mnemosynation, developed leading up to this project enables a new class of thermoset polymers with fully recoverable strains that can be mass manufactured through traditional plastics processing techniques. Thus, the broad impact of this project is two-fold: it will lay the groundwork for future injection moldable devices of complex geometries possessing shape memory and it will establish the first links between sound attenuation and crosslinker density in shape-memory polymer earpieces. Better occlusion translates into lower required listening volumes on devices such as earphones, Bluetooth hands free devices and hearing aids. This will be the first commercial proving ground for the mnemosynation manufacturing process and pave the way for a new generation of mass producible customizable ergonomic plastics with tunable shape memory properties. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).