RUI: Mechanisms of Resonant Infrared Pulsed Laser Ablation and Deposition of Polymers

聚合物薄膜在生物医学工程、化学传感和有机电子等领域有着广泛的应用需求。有机电子产品极具吸引力，其中一个原因是，它们比传统电子产品轻得多，需要的电力也更少，因此代表着下一代的可能性。这项研究中将用于沉积薄膜的技术使用了高功率红外激光，这种激光可以有效地蒸发聚合物，并将使有机电子等领域的独特研究成为可能，而这些领域通过其他手段是困难或不可能的。例如，许多感兴趣的聚合物具有较差的溶解性，因此难以加工，而本提案中的方法不要求聚合物是可溶的。在这种情况下，激光与物质的相互作用需要进一步的了解，以了解有利挥发的机制，这些研究的价值具有普遍的科学意义。聚合物的薄膜加工面临许多挑战。这里的新方法使用的是红外激光器，它被调谐到聚合物起始材料中的振动模式。这提供了一种在不发生化学变化的情况下有效地蒸发聚合物的方法，并且最大限度地减少了键断裂，并且类似于已建立的脉冲激光沉积技术，不同之处在于由于UV光子与有机物的强烈光化学作用而不使用UV激光。我们以有希望的初步结果为指导，观察到这一过程的效率甚至沉积薄膜的物理化学性质可以取决于激光激发的特定振动模式。这种特定于激光的模式行为长期以来一直受到关注。这些研究的多学科性质自然有利于更广泛的学生群体的参与。已经在塞顿霍尔参加暑期研究的SEED项目的中学生将从中受益。来自西顿霍尔生物、化学和物理系的学生将获得研究机会，教会学生跨越学科界限进行合作并有效地相互沟通。最后，塞顿霍尔大学(鲁伊的一个机构)、范德比尔特大学和海军研究实验室在这一研究领域建立了合作关系，这将为所有相关各方提供独特的机会和利益。

Polymer thin films are required for a variety of applications in such diverse areas as biomedical engineering, chemical sensing, and organic electronics. Organic electronics are extremely attractive, among other reasons, because they are much lighter than conventional electronics, and require less power and as such represent next generation possibilities. The technique that will be used to deposit films in this study uses high power infrared lasers that efficiently vaporize polymers and will enable unique studies in fields such as organic electronics that are difficult or impossible by other means. For example, many polymers of interest suffer from poor solubility and therefore are difficult to process, while the method in this proposal does not require polymers to be soluble. In this case, the laser material-interaction requires further understanding in order to understand the mechanism of favorable volatilization, and the value of these studies is of general scientific interest. Thin film processing of polymers presents many challenges. The novel approach here uses an infrared laser that is tuned to a vibrational mode in the polymer starting material. This provides a means to efficiently vaporize polymers without chemical alteration and a minimum of bond breaking, and is similar to the established technique of pulsed laser deposition, except that a UV laser is not used because of the intense photochemical interactions of UV photons with organics. We are guided by promising preliminary results, having observed that the efficiency of the process and even the physicochemical properties of the deposited films can depend on the particular vibrational mode that is excited by the laser. Such mode specific behavior with lasers has long been sought.The multidisciplinary nature of these studies naturally facilitates the participation of a wide group of students. Secondary students in Project SEED who are already participating in summer research at Seton Hall will tangentially benefit. Students from the biology, chemistry, and physics department at Seton Hall will be presented with research opportunities that will teach students to cooperate across disciplinary lines and to effectively communicate with each other. Finally, there is an established collaboration in this area of research between Seton Hall University (an RUI institution), Vanderbilt University, and the Naval Research Laboratory, which will present unique opportunities and benefits to all involved.