Research

Water is considered a relatively inner and stable molecule. We found that water molecules are rendered into reactive oxygen species (ROS), including OH·, H2O2, etc. The strong intrinsic interfacial electric field is in part responsible for the generation of ROS. Because ROS are highly reactive, the water microdroplet provides many new opportunities in a wide field of science and engineering. 

Movie: Spontaneous Generation of H2O2 in Water Microdroplet Condensates. 

Reactive oxygen species (ROS) generated from water microdroplets can kill various pathogens. Our previous studies showed that water microdroplets from spraying pure water can kill over 99.99% of Escherichia coli and Salmonella typhimurium. Currently, we are working on applying this water microdroplet-based disinfection technique to various fields, including food processing or clinical applications. This eco-friendly disinfection method would provide toxic-free treatment against bacteria-induced epidermal diseases and environmental problems.

We utilize microdroplets and microbubbles using various methods, including nebulizing spray, tip sonicator, and ultrasonic transducer. Reactive Oxygen Species (ROS) are spontaneously generated at the surface of those microdroplets and microbubbles. These ROS can be used for treating cancer because cancer cells are more vulnerable to ROS than normal cells.  When ROS concentration exceeds cellular antioxidant defense capability, the reactive species exhibit an antitumor effect by inducing oxidative stress. We are working on treating cancer cells using microdroplets and microbubble technology.

Metal nanostructures, including nanoparticles or nanowires, are spontaneously formed from metal precursor ions in water microdroplets without any added reducing agent, capping agent, or template. We utilize the microdroplet spray synthesis method for constructing metal or metal-organic hybrid or metal oxide nanostructured catalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER), and oxygen reduction reaction(ORR) used for water splitting and fuel cells.

Combining Mass Spectrometry Imaing(MSI) and Omics technologies enables in-depth investigation of biological processes at high resolution. MSI provides molecular distribution, while Omics identifies and quantifies molecules. Simultaneous studies of quantitative and spatial changes in specific proteins or metabolites within tissues through MSI and Omics enhances our understanding of complex molecular networks associated with disease onset and progression.

We are currently conducting research combining cutting-edge computing technologies, such as deep learning and artificial intelligence, with Bio Data acquired from Mass Spectrometry. Various algorithms are applied to enhance the analyses of complex biological and medical data. The goal is to unlock new insights into cell function and disease mechanisms by leveraging AI's pattern recognition and prediction power to interpret the rich dataset generated by Mass Spectrometry data and imaging.

More than 1.2 billion people globally face challenges in accessing clean drinking water. Conventional water purification processes involve oxidation, distillation, electrochemical precipitation, photocatalysis, or ion exchange. These methods often require diverse chemical reagents. We reported that the air-water interfacial electric field can generate various reactive oxygen species, which we utilize for water purification. This microdroplet technology provides a chemical-free, energy-efficient, green, and cost-effective water purification method for removing various organic and inorganic toxic compounds.

We use various fabrication techniques, including photolithography, etching, microcontact printing, self-assembly for the development of diagnostic or therapeutic biomedical devices. We are interested in developing micro-environments for seeking a mechanistic understanding of human diseases. 

Liquid-liquid phase separation(LLPS) refers to the phenomenon where two or more substances, when mixed, separate into distinct liquid phases. In biological systems, this primarily occurs within cells and contributes significantly to organizing cellular compartments and regulating various biological processes. This complex orchestration forms bimolecular condensates in cells, and these condensates consists of intrinsically disordered proteins (IDPs) which are proteins without a formation of well-defined 3D structures. We focus on investigating the dynamic interplay of LLPS at the cellular level, exploring how this process arranges the organization of cellular structures and regulates essential biochemical reactions. We aim to uncover novel insights that contribute to advancing our understanding of cellular dynamics and molecular organization in health and disease.

Observing the position and the status of biomolecules at the single-molecular level provides valuable information on the dynamics of biological systems, particularly when the system has a high level of heterogeneity. Besides, we utilize mathematical modeling of biological systems to gain a deeper understanding of the principles in which the biological systems operate or develop a testable hypothesis for experiments.

Carbon fixation is the process of taking inorganic carbon, usually CO2, and converting it to useful chemicals such as formic acid, methanol, ethanol, and ethylene. Plants utilize complex photosynthesis systems to generate glucose and oxygen from CO2 and energy from the sun. We use the unique physical and chemical properties of microdroplets to achieve carbon fixation as a new type of artificial photosynthesis system. 

We utilize the microdroplet chemistry technique to convert low-cost energy materials into efficient energy sources in an eco-friendly manner. We fabricate nanoscale structures using water microdroplets for energy conversion catalysts or directly generate and store hydrogen energy with the aqueous microdroplets. These advancements aid in creating a safe and efficient hydrogen storage technology, contributing to a sustainable energy future.