The solid-state thin-film dewetting process for nanofabrication has been mainly explored to fabricate nano-islands by agglomeration of thin film deposited on top of a substrate. This process requires heat energy on a thin film to form a nano-pattern as a driving force of surface energy. Seok Lab has successfully developed nano-island pattern structures that create periodic arrays on substrates, including silicon wafers and glass slides. Natively, lithography technology (lithography approaches; photo, atomic force, nano-implant ways) requires costly instrumentation and facilities like clean-room above class 6, mask production and aligning systems,  and chemical bench for various etching process. Therefore, this research benefits many micro/nano-applications, especially those not accessible to the high-class micro-machining facility at prominent research institutes. Final shapes and deployment from the dewetting process are limited to hemisphere and prefixed upon deposited film thickness. 

To overcome this drawback, Seok Lab plans to design standing waves of electrical or sound sources. A particular shape of waves, which has a designed wavelength/frequency and power amplitudes (in voltage), is generated and then propagates onto the thin-film surface deposited on the substrates. In every spot where multiple waves - propagating onto the surface – overlap and produce superposition behavior, the temperature increases rapidly, generating a locally concentrated thermal stress. As a result, these spots play an origin of nanostructure formation in the dewetting process. Seok defined this as 'indirect nano-indentation. At the same time, thermal energy is being radiated to the substrate to precede the dewetting process.

Design and advanced manufacturing to improve the uniformity of nano-pattern templates for bio-species identification has been being explored. Micro/nanofabrication techniques have revolutionized the pharmaceutical and medical fields. They offer highly reproducible mass fabrication of systems with complex geometries and functionalities, including novel drug delivery systems and biosensors. Through this research, Seok Lab observed that nano-patterned templates fabricated by thin-film solid-state dewetting generate the electro-magnetic field (performed by using FEM analysis) under a specific wavelength range, and this plays a role as a driving force for capturing bio-species. 

However, the size, gap, and deployment of arrayed nano-particles are not uniform. Thus, this research focuses on improving the uniformity of dimensions and particles’ density of the nano-pattern templates as an optimized prototype DNA biosensor. Seok plans to expand this research for early-stage disease detection of cancers. 

This research especially hypothesizes to replace the lateral-flow detection devices (i.e., pregnancy tester) with reusable and real-time hand-held bio-sensors. It fits well with the scope of NIH.