KSS/NMA/ACST Joint Session Speakers

Education

• B.E., M.E., Electrical Engineering, Kunsan National University, Korea

• Ph.D., Nanotechnology, Hanyang University, Korea

Short Biography

Dr. Lee received his BE and ME in Electrical engineering from the Kunsan National University, and his PhD degrees in Nanotechnology from the Hanyang University in South Korea. He received postdoctoral research training at the Institute of Nano Science and Technology (INST). During over 10 years training, he was working on fabrication and application of carbon nanotubes including vertical growth, massive production, 3D-networking, Gas sensor, Solar cell, field emission device, and microfluidic device. His current research interests encompass the field of nano - biosensors and microfluidic devices, including semiconductor-based nanostructure biosensors, lab-on-a-chip systems for biomedical applications, and modular microfluidics. Dr. Lee is a member of the KBCS (The Korean BioChip Society), the KSIEC (The Korean Society of Industrial and Engineering Chemistry), the MNS (The Society of Micro and Nano Systems), and the KONTRS (Korea Nanotechnology Research Society).

Abstract

In this presentation, I would like to introduce several nano biosensor platform technology and microfluidic device application of the National NanoFab Center (NNFC) in Korea. First, a nanostructure-based biosensor using a semiconductor process is introduced.

A case in which a three-dimensional nanopillar structure was fabricated on a silicon wafer or flexible polymer substrate and used to measure pH or analyze bacterial genes is introduced. Second, a film-based microfluidic device manufacturing technology and a fully automatic molecular diagnostic device application case using it are introduced. Finally, a modular microfluidic device platform technology is introduced. This technology composes various element technologies constituting a complex microfluidic device into each independent unit module. By unifying the interface and coupling structure of the unit module, it is possible to freely combine different materials and technologies. This technology enables low price and mass production for producers, and provides convenience, speed and scalability to users.

Short Biography

Prof. Jaehyun Hur received his B.S. in Chemical Engineering from Seoul National University, at Seoul, Korea in 2000. He received his PhD degree in Chemical Engineering from Purdue University, at West Lafayette, IN, USA in December in 2008. He had worked in Samsung Advanced Institute of Technology (SAIT) as a research scientist from 2008 to 2014. Since 2014, he has been working as an associate professor in Department of Chemical and Biological Engineering at Gachon University, Korea. His research interest is the development of high-performance photodetectors using solution-process with various functional nanomaterials.

Abstract

Ultraviolet (UV) photodetectors (PDs) have drawn significant attention because of their wide range of applications such as UV monitoring in the environment, flame sensing, missile launch detection, biological sensing, and space communications [1-2]. An ideal UV detector should satisfy the requirements of high responsivity, low noise, high spectral selectivity, repeatability with low-cost and simple fabrication process.

A solution-processed wide bandgap semiconductor-based PD with the p-n or p-i-n device configuration can provide opportunities of the fast response, high responsivity and detectivity, zero-bias operation (low power consumption), inexpensiveness, and long-term stability for the devices. In this presentation, we report new wide bandgap materials (e.g., metal oxide and metal organic framework) that can be implemented in high-performance UV PDs with vertically deposited p-n or p-i-n device structure [3-4].

Not only the good performance, but some realistic applications of these UV PDs in the partial discharge detection and continuous UV monitoring in the environment are demonstrated. In addition, the future direction for the development of UV PD will be discussed.

Short Biography

Dr. Yu-Jui Fan received his Ph. D from National Taiwan University, Institute of Applied Mechanics in 2014. He was a research assistant at University of California, Los Angeles, Mechanical and Aerospace Engineering, USA, during Mar. 2009 – Feb. 2013. He joined Taipei Medical University, School of Biomedical University as an assistant professor in December 2016. He currently is an associate professor. Dr. Fan’s research focuses on (1) developing micro environmental platform for elucidating collective cell mechanotransduction, (2) integrated microanalytical system: micro/nanofluidic device for protein preconcentrator, and directly real-time concentration quntatative immunoassay, (3) microfluidic flow cytometer.

Abstract

Preconcentration of biomolecules for detection on microfluidic platforms based on electrical kinetic trapping (EKT) through ion concentration polarization (ICP) has been well developed in the past decade. Biomolecules can be entrapped due to the equilibrium of forces between electro-osmosis and ICP when applying a voltage to the system.

However, the voltage required to trigger ICP phenomena in microfluidics is normally 30–80 V DC, which is a barrier to ICP-based nanofluidic preconcentrators becoming portable point-of-care devices. In this study, we developed a triboelectric nanogenerator (TENG)-driven nanofluidic preconcentrating device that is able to trigger ICP and subsequently cause the EKT of the biomolecules without using a conventional electrical power source. The EKT and electrical characteristics of the TENG-based nanofluidic preconcentrator were studied. Furthermore, the TENG-based nanofluidic preconcentrator was integrated with a smartphone-enabled bead immunoassay to become a portable and highly sensitive biosensor.

The preconcentration and trapping processes were developed, and the bead-immunoassay on a smartphone with/without preconcentration was demonstrated to determine the preconcentration factors.

Short Biography

Min-Hsin Yeh received his B. Sc. and M. Sc. degrees in Department of Chemical Engineering from National Taiwan University of Science and Technology (Taiwan Tech) in 2007 and 2009, respectively, and Ph.D. degree in Department of Chemical Engineering from National Taiwan University (NTU) under the supervision of Prof. Kuo-Chuan Ho in 2013. He then performed as a postdoctoral research fellow at the School of Materials Science and Engineering in Georgia Institute of Technology with Prof. Zhong Lin Wang’s research group (2014~2016).

Currently, he is an Assistant Professor in Department of Chemical Engineering of National Taiwan University of Science & Technology (Taiwan Tech) since 2018. His research interests are focused in the area of the nanomaterials and their applications in electrochemistry, photoelectrochemistry, energy harvesting systems, energy storage devices, and self-powered systems. He is also interested in the development and application of synchrotron radiation techniques and in-situ analytical techniques in nanomaterials study. He has published over 90 papers (Average IF=11.590, h-index=42; Citations ~6,300) in high impact journals such as Sci. Adv., Adv. Mater., Adv. Energy Mater., Adv. Fun. Mater., ACS Nano, Nano Energy, etc, He received awards for his acclaimed research contributions, such as Outstanding Young Scientist of the Associate of Chemical Sensors in Taiwan (2019), Young Investigator Award of the National Taiwan University of Science and Technology (2020), and Young Investigator’s Achievement Award of the Taiwan Institute of Chemical Engineers (2022).

Abstract

Emerging wearable devices with non-invasively biosensing technics have drawn considerable attention to continuously monitor several metabolites in body fluids, such as a tear, saliva, and sweat, to diagnose human health conditions. Most importantly, wearable sensors could offer unique possibilities for online, real-time and non-invasive monitoring of health compared to traditional invasive biosensors. Among lots of analytes, lactic acid concentration in the human body exhibits a high relationship with several diseases such as acute heart diseases, hypoxia, muscle fatigue, meningitis, and cystic fibrosis, and it could also cause muscle pain in athletes.

To further boost up the reproducibility and reliability of wearable biosensors to detect lactate concentration levels from human sweat, Ni-based layered double hydroxide (LDH) with various secondary transition metals (Fe and Co) was proposed as electrocatalysts in an enzyme-free electrochemical lactate sensor. According to the mechanism of lactate oxidation on the transition metal-based electrocatalyst, secondary transition metal of Co could serve as the active site for lactate oxidation and facilitate the adsorption of OH- in the alkaline electrolyte. To further increasing the active surface area for enhancing the sensitivity of Ni-based LDH, ZIF-67 derived NiCo LDH was synthesized as the electrocatalyst for non-enzymatic lactate detection. Co-based ZIF-67 served as self-sacrificial templates to fabricate hierarchically structural NiCo LDH with uniform porosity and high electrochemically active surface area to achieve outstanding electrocatalytic performance for lactate sensing.

After optimizing the particle size of ZIF-67 and transformation times, ZIF-67 derived NiCo LDH reached the ultrahigh sensitivity of 83.98 μA mM-1 cm-2 at an applied potential of 0.55 V (vs. Ag/AgCl KCl sat’d) in the concentration range from 2 to 26 mM. On the other hand, pioneering works in biosensors for lactate detection in sweat has been encountered major challenges such as noble material usage, immobile power supply, and complicated circuit connection to realize the compact sustainable sensing systems. To solve these restrictions, herein, the self-powered molecular imprinted polymers based triboelectric sensor (MIP-TES) was designed to offer a multifunctional noninvasive approach for specific and simultaneous lactate detection. Free-standing PVDF/graphene flexible electrode modified poly(3-aminophenyl boronic acid) imprinted lactate molecule demonstrated the change of the surface properties afterlactate adsorption. MIP-modified electrode revealed the selective lactate sensing over non molecular imprinted polymers (NIP) electrode through the superior and stable signal change with variation of lactate concentration in human sweat. Moreover, MIP modified lactate sensor was further introduced in the triboelectric nanogenerator system to harvest mechanical energy from contact and separation into electrical output. The more adsorbed lactate led to lower energy barriers and decreasing electrical potential when detecting higher lactate concentration. Self-power triboelectric lactate sensor could directly power the number of LED lights without an external energy supply.

Eventually, it was validated the feasible application of wearable sensors on human skin. After introducing noninvasive enzyme-free biosensors and triboelectric sensors, an innovatively continuous non-invasive health monitoring platforms can be achieved for practical applications, especially in the areas of home medical examination and wearable personal biosensors.