Collaborative Research: Transfer Printed, Single-Crystalline Si Nanomesh Thin Films

非技术描述：可伸缩电子产品已成为许多重要领域的有前途的平台，如生物仿生学、健康监测、生物医学疗法和软机器人。该项目研究了一系列基础性材料科学问题，首次为下一代可伸缩电子产品建立了一个新的电子材料平台--硅纳米颗粒。该项目的变革性方面源于纳米网格电子材料的设计和工程知识的广泛应用，不仅对基础材料科学产生了深远的影响，而且在人机接口和智能机器人方面也产生了广泛的应用。合作团队还利用该项目将创意教育活动与多层次的尖端研究相结合：(1)通过暑期研究吸引K-12学生，并在俄克拉荷马州WONDERTURM儿童博物馆举办展览；(2)积极吸引本科生进行早期研究；以及(3)东北大学和俄克拉荷马州立大学不断开发课程，以扩大软电子材料领域的能力。技术描述：可伸缩电子学的研究长期以来一直面临着设备性能和密度之间的二分法。在过去的十年里，在实现可伸缩半导体方面取得了重大进展，然而，当需要高密度、高性能的可伸展电子设备时，现有的方法仍然不完善。根据研究小组的初步结果，主要研究人员假设，利用定制的纳米网格几何结构和工程侧壁表面态，硅纳米颗粒可以同时实现高密度可拉伸电子设备所需的大可伸展、高迁移率和高可靠性。通过理论和实验两方面的研究，本项目旨在研究和建立可拉伸器件用硅纳米颗粒的结构-工艺-性能之间的相互关系。要研究的关键结构变量包括面内纳米网格图案、面外材料堆积和侧壁表面状态，而主要目标性能是机械柔韧性、可伸缩性和载流子传输迁移率。然后，该项目通过可行的自上而下的方法获得具有所需网格图案的硅纳米颗粒，打印并制造基于侧壁工程的硅纳米网格可伸展器件。一系列光学和电学相结合的表征方法系统地研究了侧壁工程硅纳米颗粒在拉伸和比例作用下的性质。除了高性能可拉伸电子学的潜在应用，这种半导体纳米网格概念还为材料工程提供了一个新的平台，并有望产生具有可调电子和光电子特性的新的可拉伸材料家族，具有定制的纳米结构。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical description: Stretchable electronics have emerged as promising platforms for many important areas such as bio-mimetics, health monitoring, biomedical therapeutics, and soft robotics. This project investigates a set of foundational materials science problems to, for the first time, establish a new electronic materials platform - Si nanomeshes - for next-generation stretchable electronics. The transformative aspect of this project arises from the broad utility of the resulting design and engineering knowledge for nanomesh electronic materials, having profound impacts to not only fundamental materials science but also a broad range of applications in human-electronic interfaces and smart robots. The collaborative team also utilizes this project to integrate creative educational activities with cutting-edge research at multiple levels through: (1) engaging K-12 students via summer research and exhibiting at Oklahoma WONDERtorium Children's museum; (2) actively attracting undergraduate students for early research; and (3) the continuous curriculum development at both Northeastern University and Oklahoma State University to expand capacity in the soft electronic materials field. Technical description: Stretchable electronics research has long been facing the dichotomy between device performance and density. In the past decade, there has been significant progress in realizing stretchable semiconductors, however, existing approaches are still incomplete when high-density, high-performance stretchable electronics are needed. On the basis of strong preliminary results from the research team, the principal investigators hypothesize that with tailored nanomesh geometries and engineered sidewall surface states, Si nanomeshes can achieve simultaneously large stretchability, high mobility and high reliability that are needed for high-density stretchable electronics. Through both theoretical and experimental investigations, this project aims to investigate and establish the interrelationship of structure-processing-properties of Si nanomeshes for stretchable devices. Key structure variables to investigate include in-plane nanomesh pattern, out-of-plane materials stacking and sidewall surface states, while main properties targeted are mechanical flexibility, stretchability, and carrier transport mobilities. The project then achieves Si nanomeshes with desired mesh patterns through viable top-down approaches, prints and fabricates sidewall engineered Si-nanomesh based stretchable devices. A set of combined optical and electrical characterizations systematically investigate the properties of sidewall-engineered Si nanomeshes under stretching and scaling. Besides potential applications for high-performance stretchable electronics, this semiconductor nanomesh concept provides a new platform for materials engineering, and is expected to yield a new family of stretchable materials having tunable electronic and optoelectronic properties with customized nanostructures.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.