Freestanding Nanomembranes towards Future Electronics
Sang-Hoon Bae
Department of Mechanical Engineering and Materials Science
Washington University in Saint Louis, MO
The conventional electronic system has been developed upon Si-based thin-films because of their cost-effectiveness and mature process. However, there are fundamental limitations in using conventional systems towards future electronics such as wearable devices, biomedical devices, and edge computing devices. One of these most prevalent limitations is that current thin-film electronic systems have been developed on rigid wafers, which causes serious physical constrains because of the thick nature of the materials on the rigid wafers. Thus, an alternative approach has been required to secure mechanically low stiffness of materials and devices.
In this talk, I will discuss about our recent effort to tackle the aforementioned challenge by developing freestanding nanomembranes. First of all, we have conceived an idea to grow single crystalline materials on graphene-coated substrates. As graphene has information transparency, crystallographic information can penetrate through graphene as long as substrate’s materials have polarity. Also, the slippery nature of graphene enables producing freestanding nanomembranes by exfoliating the grown single crystalline materials from the graphene coated substrates. Second, we have developed mechanics to produce large-scale 2D materials by playing interfacial toughness contrast. As this approach allows producing various 2D materials at large-scale, various applications can be demonstrated at practical level. As the two approaches are universal, we expect they will bring various opportunities by providing new heterostructures that would be a new platform for fundamental study and practical application.