Research

The Multiscale Multiphysics Group organizes its research by the scientific object being designed or understood. Open-surface microfluidic platforms focus on device-level liquid handling. Functional wetting surfaces focus on how surface chemistry, texture, and patterning are created. Multiphase transport and phase change focuses on the physics of droplets, particles, vapor-liquid systems, condensation, evaporation, and coupled transport. Energy and thermal management applications connect these ideas to heat pipes, thermosyphons, battery packs, electronics cooling, and compact high-performance thermal systems.

Research Themes

Selected Work by Theme

Open-Surface Microfluidic Platforms

Open-surface microfluidic platforms use engineered wetting pathways, geometry, and capillary forces to guide liquids without closed channels. Our work explores autonomous droplet transport, splitting, rapid mixing, liquid wicking in paper and fabric, and paper-based diagnostic devices for applications such as milk adulteration detection. The central goal is to convert simple surface and geometric cues into reliable microfluidic functions for sensing, sample handling, and compact analytical systems.

1. Pallab Sinha Mahapatra et al., Patterning wettability for open-surface fluidic manipulation: fundamentals and applications, Chemical Reviews, 2022.
2. Imdad Uddin Chowdhury, Pallab Sinha Mahapatra et al., Autonomous transport and splitting of a droplet on an open surface, Physical Review Fluids, 2021.
3. Subhashis Patari, Priyankan Datta, and Pallab Sinha Mahapatra, 3D Paper-based milk adulteration detection device, Scientific Reports, 2022.
4. Subhashis Patari, Imdad Uddin Chowdhury, Jitendra Kumar, and Pallab Sinha Mahapatra, Dynamics of liquid flow through fabric porous media: Experimental, analytical, and numerical investigation, Physics of Fluids, 2023.
5. Subhashis Patari and Pallab Sinha Mahapatra, Liquid wicking in the paper strip: an experimental and numerical study, ACS Omega, 2020.

Functional Wetting Surfaces

Functional wetting surfaces are created by controlling surface chemistry, roughness, wettability contrast, and hierarchical micro/nano texture. These interfaces enable wetting transitions, droplet guidance, trapped-bubble removal, fog harvesting, condensation control, and improved performance in wickless thermal devices. The work connects fabrication, surface durability, ageing, and interfacial physics to practical fluid-control strategies.

1. Tejaswi Josyula et al., Fundamentals and Applications of Surface Wetting, Langmuir, 2024.
2. Jasafa Showket et al., Fog harvesting on micro-structured metal meshes: Effect of surface ageing, Micro and Nano Engineering, 2024.
3. Laxman Kumar Malla et al., Surface Wettability Modifications and Applications in Wickless Heat Pipes, Surfaces and Interfaces, 2024.
4. Imdad Uddin Chowdhury, Pallab Sinha Mahapatra, and Ashis Kumar Sen, A wettability pattern-mediated trapped bubble removal from a horizontal liquid-liquid interface, Physics of Fluids, 2022.
5. Imdad Uddin Chowdhury, Pallab Sinha Mahapatra, and Ashis Kumar Sen, Shape evolution of drops on surfaces of different wettability gradients, Chemical Engineering Science, 2021.

Multiphase Transport & Phase Change

Multiphase transport and phase change research examines the physics that emerges when gases, liquids, solids, vapor, droplets, particles, and porous media interact. Current problems include humid-air condensation, dropwise versus filmwise modes, droplet impact on patterned wettable surfaces, particle penetration into liquid pools, wicking condensers, evaporation, and condensation on soft or nanoengineered surfaces. Thermal transport is treated through the coupled dynamics of interfaces, phase change, and mass transfer.

1. Tibin M. Thomas, Pallab Sinha Mahapatra, and Ranjan Ganguly, Atmospheric water vapor condensation on a vertical surface: Effects of confinement, Applied Thermal Engineering, 2025.
2. Prasanna Kumar Billa, Cameron Tropea, and Pallab Sinha Mahapatra, Entry and penetration of a superhydrophobic sphere into a deep pool, Physical Review Fluids, 2026.
3. Prasanna Kumar Billa et al., Motion of a rigid sphere penetrating a deep pool, Journal of Fluid Mechanics, 2025.
4. Tibin M. Thomas and Pallab Sinha Mahapatra, Wicking assisted condenser platform with patterned wettability for space application, Scientific Reports, 2023.
5. Tibin M. Thomas, Pallab Sinha Mahapatra, Ranjan Ganguly, and Manish K. Tiwari, Preferred Mode of Atmospheric Water Vapor Condensation on Nanoengineered Surfaces: Dropwise or Filmwise?, Langmuir, 2023.

Energy & Thermal Management Applications

Energy and thermal management research translates interfacial transport and phase-change physics into compact cooling technologies. The group works on flat thermosyphon heat sinks, pulsating heat pipes, minichannel and wickless heat-transfer surfaces, localized cold plates, graphite-assisted heat spreading, immersion cooling, and battery thermal management for Li-ion pouch cells. These studies combine experiments, infrared thermography, electrochemical-thermal modelling, machine-learning-based temperature-field reconstruction, and design optimization for high-performance energy systems.

1. Hemanth Dileep, Pallab Sinha Mahapatra, and Arvind Pattamatta, Lightweight thermal management strategy for Li-ion pouch cells using localised cold plate and graphite sheet, Thermal Science and Engineering Progress, 2026.
2. Shreyash Acharjee, Hemanth Dileep, Pallab Sinha Mahapatra, and Arvind Pattamatta, Full-field surface temperature reconstruction of immersion-cooled Li-ion pouch cells from sparse thermocouples using a hybrid ANN-CNN framework, International Communications in Heat and Mass Transfer, 2026.
3. Hemanth Dileep, Shreyash Acharjee, Pallab Sinha Mahapatra, and Arvind Pattamatta, Immersion cooling of lithium-ion pouch cells: Comparative heat-transfer performance of dielectric fluids with machine learning based temperature field reconstruction, Journal of Energy Storage, 2026.
4. Hemanth Dileep, Indrajith Mahadev Patil, Pallab Sinha Mahapatra, and Arvind Pattamatta, Integrated graphite-insulation sheet with cold plate for effective thermal management in pouch-type lithium-ion modules, Applied Thermal Engineering, 2025.
5. Praveen Dhanalakota, Hemanth Dileep, Laxman Kumar Malla, Pallab Sinha Mahapatra, and Arvind Pattamatta, A novel integrated flat thermosyphon heat sink for energy-efficient chip-level thermal management in data centers, Applied Thermal Engineering, 2024.

Collective & Active Matter

Collective and active matter research examines how local interactions produce organized behavior at larger scales. We study active-passive mixtures, microswimmers, particle clouds, repeated predator-prey interactions, mixing by smart active particles, segregation, and transitions between dynamical states. Simulations, modelling, and data-driven strategies are used to understand how activity, confinement, particle fraction, and interaction rules control emergent motion and transport.

1. Thomas Jacob et al., Mixing of a binary passive particle system using smart active particles, Scientific Reports, 2026.
2. Siddhant Mohapatra and Pallab Sinha Mahapatra, Behavioural response of prey to repeated attacks by non-coordinating predators, Scientific Reports, 2025.
3. Margam Ramprasad, Shubhadeep Mandal, and Pallab Sinha Mahapatra, Motion of a microswimmer in a lattice of obstacles: Effect of thermal fluctuations, Physical Review E, 2025.
4. Naveen Kumar Agrawal and Pallab Sinha Mahapatra, Alignment-mediated segregation in an active-passive mixture, Physical Review E, 2021.
5. Pallab Sinha Mahapatra et al., Transitions between multiple dynamical states in a confined dense active-particle system, Physical Review E, 2017.