Research

We develop predictive theory and computation for capillary-driven flow in micro/nanocapillaries, including effects often neglected in classical descriptions—dynamic contact line behavior and capillarity–electroosmosis coupling. By mapping distinct capillary-filling regimes—from initial inertial rise, through the viscous Lucas–Washburn regime, to an oscillatory regime near gravitational equilibrium—we provide design rules that translate directly into robust passive microfluidic architectures. These insights guide capillary networks for pumping, timing, and sensing without external actuation.
Signature contribution: 

• Regime-resolved models for capillary filling dynamics

• Contact-line and electroosmotic effects embedded in design-ready frameworks

• Passive pumping strategies for microfluidics and biosensing

• Quantitative guidance for device geometry and operating envelopes

We harness interfacial energy and drop dynamics to create ultrafast liquid–liquid encapsulation processes driven by impact and interfacial trapping. By engineering the interfacial energies of a liquid core, shell, and host bath, we enable rapid formation of encapsulated structures with controllable outcomes. This work opens routes to scalable encapsulation concepts relevant to advanced materials and formulation-driven applications in pharmaceuticals, nutraceuticals, and beyond.

Signature contribution: 

• Impact-driven encapsulation using interfacial trapping principles

• Design rules based on core–shell–bath interfacial energy balances

• Rapid formation pathways suitable for scalable processing concepts

• Application directions in formulation, delivery, and materials engineering

We create tools to measure wetting and adhesion in regimes where standard sessile-drop methods and conventional contact mechanics are limited—especially under-liquid environments, soft contacts, and extreme wettability. Our under-liquid needle-free drop deposition enables accurate contact angle measurement without needle-formed sessile drops. We also quantify droplet adhesion using a cantilever-based technique inspired by AFM, and we built a custom dual-wavelength Reflection Interference Contrast Microscopy (RICM) system to resolve soft contact mechanics and adhesion signatures. Using tunable hydrogel drops, we connect wetting to contact mechanics across the transition from liquid-drop contact to glass-sphere-like contact.

Signature contributions: 

• Under-liquid needle-free drop deposition for contact-angle metrology

• Cantilever-based droplet adhesion probing across wettability extremes

• Dual-wavelength RICM for soft contact mechanics and adhesion signatures

• Wetting–mechanics bridge using tunable hydrogel drops and soft substrates

• Quantitative methods spanning moderately wetting to superhydrophobic/oleophobic surfaces

We explore fluid and ion behavior under extreme Angstrom-scale confinement enabled by 2D materials. In this regime, water structure and interfacial interactions can fundamentally alter transport. Leveraging these effects, we develop a trapped-ion system in which ions can be trapped via confined water molecules under extreme confinement, opening new directions for sensing, purification, and energy storage. Our goal is to connect nanoscale mechanisms to device-relevant functionality.

Signature contribution: 

• Extreme-confinement transport concepts enabled by 2D materials

• Trapped-ion mechanisms mediated by water under Angstrom-scale confinement

• New frontiers for sensing and selective ion control

• Application directions spanning purification and energy storage

Our porous-media research spans length scales from microfluidic pore networks to field-scale reservoirs, with a focus on mechanistic understanding of multiphase transport in natural porous materials. We combine advanced microfluidic experimental models with computational approaches to quantify permeability, displacement patterns, interfacial effects, and electrokinetic phenomena in complex structures. A major thrust is translating pore-scale physics into improved recovery strategies, including novel enhanced oil recovery concepts such as water-alternate-emulsion flooding.

Signature contribution: 

• Microfluidic porous media as controllable analogues of natural systems

• Joint experimental–computational characterization of permeability and transport

• New EOR strategies, including water-alternate-emulsion flooding

• Mechanistic insight into multiphase displacement, trapping, and mobilization

• Electrokinetic effects integrated into porous-media transport understanding

We investigate transport, materials, and catalyst design challenges that limit the performance and durability of polymer electrolyte membrane fuel cells (PEMFCs) and water electrolyzers. Our work integrates nanoparticle synthesis, porous electrode microstructure characterization, and physics‑based transport modeling to establish clear structure–property–performance relationships. Key contributions include green and one‑pot synthesis of fuel‑cell and electrolyzer catalysts, core@shell nanoparticle architectures, high‑surface‑area carbon supports, and data‑driven machine‑learning optimization. In parallel, we develop and validate modified mass‑transport models, including Knudsen diffusion and binary friction formulations, to quantify gas transport in gas‑diffusion layers (GDLs) and catalyst layers.

Signature contributions:

• One‑pot, green, and core@shell nanoparticle synthesis for PEMFC and water‑electrolyzer catalysts

• High‑surface‑area carbon supports and catalyst layer microstructure optimization

• Data‑driven machine‑learning frameworks for catalyst performance optimization

• Quantification of Knudsen diffusivity and permeability in GDL and GDL/MPL structures

• Modified binary friction models for mass transport in porous fuel‑cell components

Reservoir-on-Chip is an experimental platform built to observe water–oil–gas displacement processes as they happen within reservoir-relevant porous structures. By enabling in situ visualization and quantification of multiphase transport, the platform reveals displacement pathways, trapping mechanisms, and interfacial dynamics that are otherwise difficult to access in opaque natural materials. This chip-based approach supports direct testing of recovery concepts and provides a bridge between pore-scale physics and reservoir-scale performance.

Signature contribution: 

• In situ observation of water–oil–gas displacement processes

• Quantification of displacement efficiency, trapping, and flow pathways

• Platform for evaluating recovery strategies under controlled conditions

• A pore-scale window into reservoir-scale transport behavior

We develop field-deployable diagnostic workflows that make drinking-water safety faster and more accessible. The Mobile Water Kit is a portable, rapid detection system designed to identify waterborne pathogens in real-world settings, supporting timely decision-making where lab infrastructure is limited. Our focus is on practical performance—speed, reliability, and usability—while maintaining scientific rigor in transport, sampling, and detection design.

Signature contribution: 

• Portable workflows for rapid pathogen detection in drinking water

• Designs optimized for low-resource and field conditions

• Emphasis on reliability, usability, and actionable results

• Technology that supports community-scale water quality monitoring

We develop microfluidic and optical biosensing platforms for rapid, sensitive detection in food safety and healthcare, paired with robust bio-functionalization strategies that improve specificity and reduce false results. Our work includes a Mach–Zehnder Interferometer (MZI) biosensor based on total internal reflection (TIR) for real-time detection of Listeria monocytogenes to reduce contamination risk in ready-to-eat products. We also build multiplex microfluidic detection approaches for cardiac biomarkers from small volumes of serum and advance surface chemistries (physisorption/chemisorption/bioaffinity) and microstructured interfaces (e.g., MSIP) for efficient immobilization and reliable sensing.

Significant contributions:

• Foodborne pathogen detection: Designed and tested an MZI–TIR biosensor for rapid, real-time detection of Listeria monocytogenes, supporting reduced contamination risk in ready-to-eat (RTE) products.

  Cardiac diagnostics (multiplex): Developed a rapid, accurate, highly sensitive system for simultaneous detection of myoglobin, troponin I, troponin T, and CK‑MB from a small amount of blood serum to enable early heart-attack diagnosis.

• Multiple sensing modalities: Investigated microfluidic sensing approaches including colorimetric, fluorescence, dielectrophoresis, impedance, and microcantilever methods for biomarker detection and robustness.

• Biofunctionalization science: Studied biomolecule immobilization on silicon surfaces to maximize sensitivity and minimize denaturation, cross-binding, non-specific adsorption, and non-uniform distribution (reducing false positives/negatives).

• MSIP-enabled detection: Demonstrated an efficient diagnostic approach using chemically modified Micro‑Spot with Integrated Pillars (MSIP) for Dengue virus NS1 detection.