SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project will focus on the understanding, development, and commercialization of new ultra-softening shape memory polymer (SMP) systems for use as novel earpiece materials. Currently, earpieces such as earphones and earplugs utilize tough, semi-rigid polymers that are often poor fitting, uncomfortable and must be produced via conventional molding technology. SMPs possess several key properties that render them attractive alternatives to conventional materials such as their ability to soften dramatically with heat and their ability to be optically cured. Through adjustments in the composition of SMP systems, thermomechanical properties such as the temperature and amount of softening can be significantly and controllably tailored according to the intended application. The softening that the earpieces experience after insertion will result in the ability to conform to the exact shape of the ear canal, improving comfort and audio performance. Pending success of this project, we will have developed the first shape memory material that can be rapidly cured with light into complex 3-D shapes with sub 100 micrometer feature sizes using stereolithography, which is viscoelastic at both room temperature and body temperature and softens an order of magnitude between the two. The broader impact/commercial potential of this project is built around the fact that we are introducing a completely new technology which will enable real time manufacturing of custom components with application specific thermomechanical properties. While the overarching goals of this proposal are specific to demonstrating custom ultra-softening viscoelastic earpieces with superior comfort and audio quality with easy insertion, the technology developed here will benefit numerous industries and society as a whole. For example, we envision this technology being used in remote locations where businesses have need for softening elastic and viscoelastic materials in specified geometries such as gaskets, heat-shrinkable tubes, seals, grips, etc. Furthermore, this technology could be monumental in the medical field by enabling hospitals to create custom biomedical devices on-site as needed, designed specifically for the patient. Eliminating the need to order specialty parts from a separate location will reduce time and cost associated with medical device implantation. In addition, a successful project will benefit the scientific community by providing peer reviewed publications introducing novel shape memory material with highly tailorable thermomechanical properties according to composition, thus stimulating additional research in field of SMP systems and applications.

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is making tough, 3D printed parts that can be directly manufactured through additive processes commercially available. Additive manufacturing has potential to revolutionize the way parts are produced by streamlining product design, production, and validation, which allows for low production costs and accelerated lead times. The penetration of additive technology into industrial processes has been greatly slowed by the current inability to 3D print parts of any stiffness with materials properties on par with traditionally manufactured parts. Particularly, 3D printed materials tend to tear or fracture more readily between successive printed layers. At Adaptive 3D Technologies, we have developed resins that produce tough, robust parts that are tougher than many current 3D printed products in the x, y and z planes by achieving covalent crosslinking across printed layers. These materials and processing techniques will help drive additive manufacturing into large volume, yet customizable, market sectors to increase efficiency and productivity across industries. The printed parts resulting from our printable materials will further U.S. manufacturing by lowering production costs, increasing product performance and reshoring advanced manufacturing. This project is focused on understanding interface chemistry and adhesion phenomena in a special class of low-viscosity, thiol-ene resins to produce a range of mechanically tough materials that are 3D printable via stereolithography (SLA). A significant problem with current SLA approaches is that successive printed layers do not adhere sufficiently together, leading to large reductions in toughness as measured by the stress-strain response in soft, viscoelastic and stiff materials. Our Phase II research explores the tradeoffs between molecular architecture, reactivity, resin viscosity, and key printing parameters to develop improved materials to enable tougher printed parts than industry standards along multiple axes of deformation at similar printing speeds and feature sizes well below 100 microns. We have developed a portfolio of 3D printable materials with room temperature Young's moduli near 2 MPa, 20 MPa, 200 MPa or 2 GPa. Soft and viscoelastic materials have strain capacities well above 100% in all print directions, including when measured perpendicular to print layer interfaces. We expect to further our polymers' thermomechanical properties through the proposed Phase II SBIR effort by incorporating proper additives into our systems to control color, shelf life, aesthetics, mechanical properties and compatibility with various jetting techniques.