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

这个小型企业创新研究（SBIR）第二阶段项目支持开发一种独特的制造方法，以生产复杂形状的新型形状记忆聚合物。 这些智能材料可以“记忆”，并在外部刺激下改革成固定的形状。 这种连续制造工艺比目前最先进的方法效率高得多，使形状记忆聚合物的许多低成本应用成为可能。 该项目将开发形状记忆聚合物耳塞，由用户的耳朵热激活，并不断适应和自我调整，以定制适合任何大小的耳道。 目前用于耳塞的材料解决方案具有若干缺点，包括不能控制耳塞施加在敏感的内耳区域上的力，该力随着时间的推移而引起疼痛。 这项工作将解决扩大低成本制造工艺的技术挑战，并建立能够优化其声学性能的配方。 将进行人类受试者测试，以主观验证舒适度，客观验证耳道尺寸差异很大的衰减。 如果成功，该项目将产生一个具有优化的声学特性和舒适性的设备，准备用于首次商业销售。该项目的更广泛/商业影响是大规模生产的形状记忆聚合物设备的影响。由于其所需的性能，形状记忆聚合物越来越多地用于生物医学应用，但其更广泛地应用于大众市场受到成本和几何约束的限制。 如果成功，该项目将建立一种新的制造工艺，通过改进传统的塑料加工技术，可以大规模生产一类新的聚合物。因此，该项目的广泛影响是双重的：它将在形状记忆聚合物耳机中建立声音衰减和交联剂密度之间的第一个联系，并且它将为未来复杂几何形状的低成本形状记忆器件奠定基础。 预期更好的闭塞和更舒适的耳塞能够在嘈杂的工业环境中更高地使用保护性听力设备。 这反过来又解决了工业部门日益严重的噪声性听力损失问题，根据OSHA的说法，这是当今美国的头号职业病。 此外，形状记忆耳塞可能会使其他用户受益，包括音乐家，专业运动员和自闭症儿童。这项技术也可以适用于类似的设备，包括手机耳机，蓝牙音频设备和助听器。

This Small Business Innovation Research (SBIR) Phase II project supports the development of a unique manufacturing method to produce novel shape memory polymers in complex shapes. These smart materials can "remember" and reform to a set shape upon an external stimulus. This continuous manufacturing process is vastly more efficient than the current state-of-the-art methods, enabling many low cost applications of shape memory polymers. This project will develop shape memory polymer earplugs that are heat activated by the user's ear and continuously adapt and self-adjust to custom fit any size ear canal. Current material solutions for earplugs suffer from several drawbacks, including an inability to control the force exerted by the earplug upon sensitive inner ear regions that cause pain over time. This effort will address the technical challenges of scaling up the low cost manufacturing process and establish formulations that will enable optimization of its acoustic performance. Human subject testing will be conducted to subjectively validate comfort and objectively validate attenuation with very differently sized ear canals. If successful, this project will yield a device with optimized acoustic properties and comfort ready for first commercial sale.The broader/commercial impact of this project is the impact of a mass-manufactured shape memory polymer device. Due to their desired properties, shape memory polymers are increasingly used in biomedical applications, but their broader adoption into mass markets has been limited by cost and geometry constraints. If successful, this project will establish a novel manufacturing process that, through modified traditional plastics processing techniques, can mass manufacture a new class of polymers. Thus, the broad impact of this project is twofold: it will establish the first links between sound attenuation and crosslinker density in shape memory polymer earpieces, and it will lay the groundwork for future low cost shape memory devices of complex geometries. Better occlusion and more comfortable earplugs are expected to enable higher usage of protective hearing devices in loud industrial settings. This in turn addresses the growing problem of noise-induced hearing loss in the industrial sector, which according to OSHA, is the number one occupational disease in the US today. In addition, shape memory earplugs may benefit other users including musicians, professional athletes and children with autism. This technology can also be adapted to similar devices including cell phone headsets, Bluetooth audio devices, and hearing aids.