Luo Hongyu, Wang Chengjun, Linghu Changhong, Yu Kaixin, Wang Chao, Song Jizhou
Department of Engineering Mechanics, Soft Matter Research Center, and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
Natl Sci Rev. 2020 Feb;7(2):296-304. doi: 10.1093/nsr/nwz109. Epub 2019 Aug 6.
Transfer printing, as an important assembly technique, has attracted much attention due to its valuable merits to develop novel forms of electronics such as stretchable inorganic electronics requiring the heterogeneous integration of inorganic materials with soft elastomers. Here, we report on a laser-driven programmable non-contact transfer printing technique via a simple yet robust design of active elastomeric microstructured stamp that features cavities filled with air and embedded under the contacting surface, a micro-patterned surface membrane that encapsulates the air cavities and a metal layer on the inner-cavity surfaces serving as the laser-absorbing layer. The micro-patterned surface membrane can be inflated dynamically to control the interfacial adhesion, which can be switched from strong state to weak state by more than three orders of magnitude by local laser heating of the air in the cavity with a temperature increase below 100°C. Theoretical and experimental studies reveal the fundamental aspects of the design and fabrication of the active elastomeric microstructured stamp and the operation of non-contact transfer printing. Demonstrations in the programmable transfer printing of micro-scale silicon platelets and micro-scale LED chips onto various challenging receivers illustrate the extraordinary capabilities for deterministic assembly that are difficult to address by existing printing schemes, thereby creating engineering opportunities in areas requiring the heterogeneous integration of diverse materials such as curvilinear electronics and MicroLED displays.
转移印刷作为一种重要的组装技术，因其在开发新型电子形式方面的宝贵优点而备受关注，这些新型电子形式包括需要将无机材料与软弹性体进行异质集成的可拉伸无机电子器件。在此，我们报告一种激光驱动的可编程非接触转移印刷技术，该技术通过一种简单而稳健的有源弹性体微结构印章设计实现，其特征在于具有填充空气并嵌入接触表面下方的腔体、封装空气腔体的微图案化表面膜以及位于内腔表面用作激光吸收层的金属层。微图案化表面膜可动态膨胀以控制界面附着力，通过对腔体内空气进行局部激光加热，在温度升高低于100°C的情况下，界面附着力可从强状态切换到弱状态，变化幅度超过三个数量级。理论和实验研究揭示了有源弹性体微结构印章的设计与制造以及非接触转移印刷操作的基本方面。将微尺度硅片和微尺度LED芯片可编程转移印刷到各种具有挑战性的接收器上的演示，展示了现有印刷方案难以实现的确定性组装非凡能力，从而在需要不同材料异质集成的领域创造了工程机会，如曲线电子学和MicroLED显示器。
