Harnessing Light to Control the Autonomous Functionality of Soft Active Materials

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 使用理论和模拟，我们的目标是设计涂层，允许控制的时空调制的表面特性，从而赋予仿生功能的广泛的系统。 在这些研究中，我们将利用聚合物凝胶进行Belousov-Zhabotinsky（BZ）反应的独特行为。 BZ凝胶是目前唯一已知的显示自主机械振荡的聚合物网络。 此外，BZ反应是光敏的，通过改变光强度，我们可以操纵材料的响应。 正是这种化学响应聚合物网络和光敏反应之间的相互作用，我们将利用直接的自我持续的运动的凝胶。 通过用这些BZ凝胶的薄膜或系留细丝涂覆表面，我们可以赋予所得到的系统诸如自主感测、致动和重构的特性。 在这些应用中，光作为控制机制提供了有用的优点：它允许远程调节的手段，是一种清洁能源，可以很容易地打开或关闭。如果成功，研究结果将揭示非线性动力学现象，可以产生于化学，光学和机械能的耦合，并建立设计规则，用于创建毫米级器件，这些器件在其自身的功率下有效地运行，以执行有价值的功能。 此外，该研究将产生计算模型，使用户能够设计和预测包含活性成分的软材料的特性。 为鼓励更多学生参与本科生研究工作，以及让已从事研究工作的本科生熟悉同事的活动，研究所将为邻近大学举办为期一天的本科生研究海报展览。 当地高中的学生也将被邀请参加。 本科研究人员将特别有效地与这个年轻的群体，并可以在鼓励9- 12年级学生在大学里追求科学和工程方面发挥重要作用。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Using theory and simulation, our goal is to design coatings that permit the controlled spatial-temporal modulation of surface properties and, thereby, impart biomimetic functionality to a broad range of systems. In these studies, we will take advantage of the distinctive behavior of polymer gels undergoing the Belousov-Zhabotinsky (BZ) reaction. The BZ gels are currently the only known polymer networks to display autonomous mechanical oscillations. Furthermore, the BZ reaction is photosensitive and by varying the light intensity, we can manipulate the response of the material. It is this interplay between the chemo-responsive polymer network and the photosensitive reaction that we will exploit to direct the self-sustained movement of the gels. By coating a surface with thin films or tethered filaments of these BZ gels, we can confer to the resulting systems such properties as autonomous sensing, actuation and reconfiguration. In these applications, light provides useful advantages as a control mechanism: it permits a means for remote regulation, is a clean energy source and can be easily turned on or off.If successful, the findings will reveal nonlinear dynamical phenomena that can arise from a coupling of chemical, optical and mechanical energy, and establish design rules for creating millimeter-scale devices that effectively operate under their own power to perform valuable functions. In addition, the study will produce computational models that enable users to design and predict the properties of soft materials that encompass active components. To encourage the participation of more students in undergraduate research and to let undergrads already engaged in research become familiar with the activities of their colleagues, the PI will organize a day-long Undergraduate Research Poster Fair for the nearby universities. Students from local high schools will also be invited to attend. The undergraduate researchers would be particularly effective at relating to this younger cohort and could play an important role in encouraging the 9-12th graders to pursue science and engineering in college.