Our research focuses on developing functional materials for bio medical application and device application. We mainly study 1) Microneedle Patch, 2) Nanofabrication-based Application, 3) Membrane-based Bio-Nano Technologies.

1) Microneedle for Skin tissue Adhesive
Microneedles create tiny pores in the stratum corneum of skin tissue by piercing it with micron size needles and because these devices are not long enough to stimulate the underlying nerve endings, use of microneedles is completely painless. A bio-inspired microneedle adhesive provides a new platform for adhesion based on mechanical interlocking. Chemical adhesives, such as cyanoacrylate, adhere strongly to tissues but lead to an intense inflammatory response. Although sutures and staples are typically used to tissue adhesives, they can cause significant tissue damage, scarring, and excessive depth of tissue penetration can result in nerve and blood vessel damage. Microneedle adhesive exhibits universal adhesion to soft tissues regardless of surface chemistry and it mechanically interlocks with tissues without significant damage while providing an effective barrier to bacteria. Microneedle adhesive may serve as an effective drug delivery vehicle to enhance the penetration of drugs into tissue. As drugs can easily be loaded into the swellable tips during swelling, within an agent doped solution (followed by deswelling to return to a stiff state), microneedle adhesive can administer multiple types of agents directly into the wound microenvironment in a minimally invasive manner.

Bio-Inspired Microneedle Patch

Microneedle for transdermal drug delivery

(S. Y. Yang et al., Nat. Commun., 4, 1-10, (2013))

2) Nanofabrication-based Applications
SERS substrates for bio sensor: SERS(surface-enhanced Raman scattering) has been considered attractive method for detecting analytes at low concentration and bio molecules because of its various advantages such as single molecule level sensitivity, unique vibration spectra and insensitive to water. Nanofabrication techniques are great methods for fabricating nanostructures for SERS active substrate because they effectively control geometrical shapes to demonstrate SERS effect. We are trying to fabrication of SERS active substrates using our novel nanofabrication technologies with facilities for chemical sensor and bio sensor.

Nanotips array fabrication: Nanotip or nanocone structures on a substrate have received significant interest for their broad applications such as antireflection, sensing elements, and functional surfaces. We study various method to fabricate functional organic/inorganic nanotips on substrate in a large area (>inch scale). Currently, we report a facile method to fabricate free-standing polyimide (PI) nanotips on substrates by using plasma treatment with oxygen gas. To demonstrate potential application of PI nanotips as a template for hollow nanostructures, hollow TiO2 nanotips were prepared after atomic layer deposition of TiO2 followed by the burning of PI layer.

 
3) Membrane-based Bio-Nano Technologies

Membrane which serves as a selective barrier between two phases is being utilized in various fields owing to its efficiency, ease of implementation, and cost effectiveness. For this reason, many researchers are actively studying it in the laboratory as well as the industrial sector. We have developed nanoporous membranes with pore sizes ranging from a few to several hundred nanometers by using self-assembly polymer and anodic aluminum oxide (AAO) for virus filter, drug delivery device, bio sensor and so on.

※ Instruments
Spin Coater, Rotary Evaporator, Centrifuge, Fluorescence Microscope, Plasma Etching Machine, Universal Testing Machine, Contact Angle Meter, Digital temperature controller, Gas sensor, UV exposure Lamp, Sonicator