EAGER: Measurements of Soft Bi-material Interface Behaviors under Dynamic Loading Conditions

聚合物薄膜广泛应用于柔性电子和软机器人。这些聚合物薄膜界面的耐久性对其长期性能至关重要。透彻了解这些薄膜的性质在微电子制造中也很重要，在微电子制造中，纳米结构聚合物薄膜图案用于制造复杂的电路。随着这些工艺的生产率的提高，对这些薄膜模式动态性能的理解变得越来越重要。这项早期概念探索性研究（EAGER）奖支持基础研究，以创建一种新的实验技术来测量动态负载条件下聚合物薄膜中材料特性梯度的特性。本研究将产生动态加载条件下材料性能梯度和界面条件的关键实验数据。这些数据可以用于增强这些材料系统的计算建模，并使新的多层膜系统的设计成为可能。这项研究的见解也将推动新的制造策略，以提高工程柔性部件的长期性能。其性能的提高将直接影响到美国的软机器人、制造业和医疗保健系统，为皮肤安装的传感器和柔性机器人提供更耐用的设备。该项目将提供机会，教育和培训研究生先进的实验技术，可应用于许多工程领域。该项目还将通过对本科生的研究经验影响本科教育，重点关注代表性不足的学生。聚合物薄膜和多层薄膜的性能在很大程度上取决于材料性能通过薄膜厚度的梯度。由于与衬底的化学相互作用和几何限制，这些性质相对于大块聚合物材料发生了变化。同样，聚合物基复合材料的失效和动态行为往往由增强材料和基体材料之间的界面/界面特性决定。本研究旨在实现、演示和评估一种新的基于声学的实验技术，用于同时测量软、双材料界面附近厚度的应力-应变行为梯度以及这些界面上的粘附性能。两种特定的材料系统将被处理，聚合物薄膜和聚合物基复合材料的相间区。材料性能数据将在大范围的动态加载条件下收集。该研究结果将为力学研究人员提供一种新的实验方法，通过显著减少局部界面条件和衬底材料的影响，更准确地确定薄膜和界面试样在厚度方向上的性能变化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Thin polymer films are widely used in flexible electronics and soft robotics. The durability of these thin polymer film interfaces is critical to their long-term performance. A thorough understanding of the properties of these films is also important in microelectronics fabrication where nanostructured polymer thin film patterns are used to fabricate complex circuitry. As production rates for these processes increase, an understanding of the dynamic performance of these thin film patterns becomes more and more critical. This EArly-concept Grant for Exploratory Research (EAGER) award supports fundamental research to create a new experimental technique to measure the properties of material property gradients in polymer thin films under dynamic loading conditions. This research will generate critical experimental data on material property gradients and interface conditions under dynamic loading conditions. This data can be used for the enhancement of computational modeling of these material systems and enable the design of new multi-layer film systems. Insight from this research will also drive new fabrication strategies to enhance the long-term performance of engineered flexible components. Enhancements to their performance would directly impact the nation's soft robotics, manufacturing and healthcare systems by enabling more durable devices for skin mounted sensors and flexible robots. This project will provide opportunities to educate and train graduate students in advanced experimental techniques that could be applied across many engineering fields. The project will also impact undergraduate education through research experiences for undergraduates with a focus on underrepresented students. The performance of thin polymer films and multi-layer films depends highly on the gradient of material properties through the thickness of the film. These properties are altered relative to the bulk polymer material due to chemical interactions with the substrate and geometrical confinement. Similarly, the failure and dynamic behavior of polymer-matrix based composites is often dominated by the interface/interphase properties between the reinforcement and the matrix materials. This research aims to implement, demonstrate and evaluate a novel acoustics based experimental technique for the simultaneous measurement of stress-strain behavior gradients through the thickness near soft, bi-material interfaces and adhesion properties at these interfaces. Two specific material systems will be addressed, polymer thin films and the interphase region in polymer-matrix composites. Material property data will be collected over a wide range of dynamic loading conditions. The outcome of this research will be a new experimental method for mechanics researchers to more accurately determine property variations in the thickness directions for thin-film and interphase specimens by significantly reducing the effects of the local interface conditions and the substrate material.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.