Photoswitchable Polymers for 2-Step Dry Transfer of 2D Materials

用于 2D 材料两步干转移的光开关聚合物

• 批准号: 2110526
• 负责人: Kenneth Liechti
• 金额: $ 59.93万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110526&HistoricalAwards=false
• 关键词: Photoswitchable; Polymers; Step; Dry; Transfer

Graphene and other atomically thin materials have very attractive mechanical, electrical and thermal properties and their mass production via chemical vapor deposition has greatly improved the opportunities to scale up the production of devices that employ them. However, before these materials can be used, they need to be transferred from their growth substrate to a target substrate for microelectronics devices. This award addresses the transfer step, which is a roadblock to manufacturing scalability. Historically, transfer has been accomplished by so-called wet methods, where the growth substrate is dissolved away. These are slow, wasteful, and often lead to relatively high levels of contamination. Dry transfer methods developed here provide an attractive rapid and “cleaner” alternative. Because these materials are so thin, they need to be supported at all times and polymers are an attractive medium for removing the materials from their growth substrate and depositing them on the target substrate. High and low adhesion is required for the first and second steps, respectively. The challenge being addressed in this award is the development of novel polymers, whose adhesion can be switched on or off by shining light on them. It is expected that successful development of such polymers will place the US in a leadership role in manufacturing these atomically thin materials and promote the fabrication of next generation electronics to be found in phones, computers, cars and televisions. There is extensive educational outreach to K-12 and STEM audiences that highlights switchable adhesion and the polymers developed in the course of the research.The goals of the research are to (i) develop a new class of photoswitchable adhesives that is tailored specifically to the 2-step, dry transfer of graphene via (ii) a thorough and deep characterization of the interactions of all the interfaces that play a role in the transfer process and (iii) the design and fabrication of a separation tool that is common to both transfer steps based on the understanding obtained in the first two steps. This multidisciplinary effort is highly coupled in that the development of this class of polymers will be guided by both the characterization and tool development efforts, which will both feedback into the fine tuning of composition, architecture and associated adhesion characteristics of the polymers. From a fundamental materials perspective, the impact of polymer composition and architecture (e.g., networks vs surface-bound brushes) on the photoresponsive change in order and topology will be unveiled and inform the design of next generation “smart” adhesives. These light-responsive adhesive characteristics will be judiciously characterized and applied to the efficient, large area 2-step dry (patterned) transfer of graphene using an innovative and efficient advanced manufacturing process.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.

石墨烯和其他原子级薄材料具有非常有吸引力的机械、电学和热学性质，并且它们通过化学气相沉积的大规模生产极大地提高了扩大使用它们的设备的生产的机会。然而，在使用这些材料之前，它们需要从它们的生长衬底转移到微电子器件的目标衬底。该奖项解决了转移步骤，这是制造可扩展性的一个障碍。历史上，转移已经通过所谓的湿法完成，其中生长基质被溶解掉。这些都是缓慢的，浪费的，并往往导致相对较高的污染水平。这里开发的干转移方法提供了一种有吸引力的快速和“清洁”的替代方案。由于这些材料非常薄，因此它们需要始终被支撑，并且聚合物是用于从其生长基底移除材料并将其沉积在目标基底上的有吸引力的介质。第一和第二步骤分别需要高和低的粘附力。该奖项所面临的挑战是开发新型聚合物，其粘合力可以通过光照来打开或关闭。预计这种聚合物的成功开发将使美国在制造这些原子级薄材料方面发挥领导作用，并促进下一代电子产品的制造，这些电子产品将用于电话、计算机、汽车和电视机。有广泛的教育推广到K-12和STEM观众，突出了可转换粘合剂和研究过程中开发的聚合物。研究的目标是（i）开发一类新的光可转换粘合剂，专门针对2步，通过（ii）对在转移过程中起作用的所有界面的相互作用进行彻底和深入的表征，以及（iii）基于在前两个步骤中获得的理解，设计和制造两个转移步骤共用的分离工具。这种多学科的努力是高度耦合的，因为这类聚合物的开发将受到表征和工具开发工作的指导，这两者都将反馈到聚合物的组成，结构和相关粘附特性的微调中。从基本材料的角度来看，聚合物组成和结构（例如，网络与表面结合的刷子）的顺序和拓扑结构的光响应变化将被揭开，并通知下一代“智能”粘合剂的设计。这些光响应粘合剂特性将被明智地表征，并应用于使用创新和高效的先进制造工艺的石墨烯的高效，大面积两步干燥（图案化）转移。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。