Inside the experiments
Interfaces in motion
From droplet impact to frost formation and particle entry: a closer look at our multiphase-flow experiments.
Droplet impact on surfaces
Watch the droplets approach, impact, and evolve at the interface.
Frost formation
Experimental views of ice structures and surrounding droplets, bringing our work on condensation and freezing into focus.
Explore phase-change research →
Particle entry & cavity dynamics
Two experimental views of particle entry into liquid, showing the splash and cavity formed at the air–water interface.
Explore multiphase-flow research →Selected Work by Theme
Multiphase Transport & Phase Change
We study how liquid, gas, and solid phases interact through moving interfaces, capillary forces, and coupled heat and mass transfer. Condensation, frosting, and boiling form a central part of this work. Our recent frosting research combines controlled experiments with complex-network analysis to characterize the evolution of condensation frosting. Complementary studies of droplet impact, bubble and cavity dynamics, and particle entry into liquid pools address multiphase flows without requiring phase change. Experiments, high-speed imaging, thermal measurements, and numerical modelling connect these mechanisms to water harvesting and thermal systems.
Condensation
Vapor-to-liquid phase change, condensate removal, surface wettability, and heat and mass transfer in humid air.
Condensation study (2025)Frosting & freezing
Controlled experiments and complex-network analysis of ice nucleation, bridging, and frost growth on engineered surfaces.
Frosting study (2026)Boiling
Liquid-to-vapor phase change, bubble dynamics, and heat transfer on structured surfaces.
Pool-boiling study (2025)- Ashok Kumar Raipilli, Manish Kumar Manna, Nirmal Manyani, Sourav Sarkar, Achintya Mukhopadhyay, Arvind Pattamatta, and Pallab Sinha Mahapatra. Unraveling Condensation Frosting through Controlled Experiments and Complex Networks. Langmuir, 2026.
- Prasanna Kumar Billa, Cameron Tropea, and Pallab Sinha Mahapatra. Entry and penetration of a superhydrophobic sphere into a deep pool. Physical Review Fluids, 2026.
- Tibin M. Thomas, Pallab Sinha Mahapatra, and Ranjan Ganguly. Atmospheric water vapor condensation on a vertical surface: Effects of confinement. Applied Thermal Engineering, 2025.
- Mohd Zahid, Ashok Kumar Raipilli, Arvind Pattamatta, and Pallab Sinha Mahapatra. Sustainable humid air condensation: insights into nanoengineered surfaces. ACS Applied Materials & Interfaces, 2025.
- Praveen Dhanalakota, Md Motiur Rahaman, Pallab Sinha Mahapatra, Anand A. R., Sarit K. Das, and Arvind Pattamatta. Insights into Pool Boiling Heat Transfer on Minichannel Surfaces through Point and Field Measurements. ASME Journal of Heat and Mass Transfer, 2025.
- Ashok Kumar Raipilli, Nishith Balagirithar, and Pallab Sinha Mahapatra. Droplet impact on patterned wettable surface: Experiments and numerical analysis. Physics of Fluids, 2025.
- Prasanna Kumar Billa, Tejaswi Josyula, Cameron Tropea, and Pallab Sinha Mahapatra. Motion of a rigid sphere penetrating a deep pool. Journal of Fluid Mechanics, 2025.
Functional Wetting Surfaces
Surface engineering is used to control liquid interaction through surface chemistry, hierarchical micro/nano texture, coatings, and spatial variations in wettability. A key direction is the development of PFAS-free superhydrophobic surfaces that provide strong water repellency without relying on persistent fluorinated compounds. We also design patterned wettabilities that create controlled wetting contrasts for droplet guidance, impact control, trapped-bubble removal, condensation management, and open-surface fluid transport. The work connects fabrication, durability, ageing, and interfacial physics to practical fluid-control and thermal applications.
Surface engineering
Surface chemistry, coatings, roughness, and hierarchical texture are tailored to control wetting, adhesion, spreading, and repellency.
Surface-wetting fundamentalsPFAS-free superhydrophobic surfaces
Fluorine-free nanoengineered surfaces combine water repellency with a more sustainable route to condensation and liquid control.
PFAS-free surface studyPatterned wettabilities
Hydrophilic and hydrophobic patterns create spatial wetting contrasts that guide, split, retain, or redistribute droplets.
Patterned-wettability review- Mohd Zahid, Ashok Kumar Raipilli, Arvind Pattamatta, and Pallab Sinha Mahapatra. Sustainable humid air condensation: insights into nanoengineered surfaces. ACS Applied Materials & Interfaces, 2025.
- Tejaswi Josyula, Laxman Kumar Malla, Tibin M. Thomas, Srinivasa Sagar Kalichetty, Pallab Sinha Mahapatra, and Arvind Pattamatta. Fundamentals and Applications of Surface Wetting. Langmuir, 2024.
- Jasafa Showket, Shibangi Majumder, Nirbhay Kumar, Soumyadip Sett, and Pallab Sinha Mahapatra. Fog harvesting on micro-structured metal meshes: Effect of surface ageing. Micro and Nano Engineering, 2024.
- Laxman Kumar Malla, Praveen Dhanalakota, Hemanth Dileep, Pallab Sinha Mahapatra, and Arvind Pattamatta. Surface Wettability Modifications and Applications in Wickless Heat Pipes. Surfaces and Interfaces, 2024.
- 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.
- Pallab Sinha Mahapatra, Ranjan Ganguly, Aritra Ghosh, Souvick Chatterjee, Sam Lowrey, Andrew D. Sommers, and Constantine M. Megaridis. Patterning wettability for open-surface fluidic manipulation: fundamentals and applications. Chemical Reviews, 2022.
- Imdad Uddin Chowdhury, Pallab Sinha Mahapatra, and Ashis Kumar Sen. Shape evolution of drops on surfaces of different wettability gradients. Chemical Engineering Science, 2021.
Open-Surface Microfluidic Platforms
Open-surface microfluidic platforms use engineered wetting pathways, porous substrates, geometry, and capillary forces to guide liquids without closed channels. A major direction is paper-based microfluidics for low-cost diagnostics. Our 3D paper device routes a small milk sample to multiple colorimetric detection zones and simultaneously screens seven adulterants, while related studies establish the liquid-wicking physics of paper and fabric. We also develop droplet transport, splitting, and mixing strategies for compact sensing and sample handling.
Paper-based microfluidics
Capillary wicking, porous transport, and three-dimensional paper flow paths for passive liquid handling.
Paper-wicking studyMilk adulteration detection
A compact 3D paper device that simultaneously screens seven common milk adulterants using colorimetric detection zones.
Milk-detection deviceMilk safety sensing
Fluorescence and sensor strategies for sensitive aflatoxin detection and safer milk-quality assessment.
Aflatoxin-sensing review (2026)- Soorya Srinivasan, Sonu K. Shivanna, and Pallab Sinha Mahapatra. Fluorescence, sensors, and safety: The new era of aflatoxin detection in milk. Journal of Food Measurement and Characterization, 2026.
- 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.
- Subhashis Patari, Priyankan Datta, and Pallab Sinha Mahapatra. 3D Paper-based milk adulteration detection device. Scientific Reports, 2022.
- Pallab Sinha Mahapatra, Ranjan Ganguly, Aritra Ghosh, Souvick Chatterjee, Sam Lowrey, Andrew D. Sommers, and Constantine M. Megaridis. Patterning wettability for open-surface fluidic manipulation: fundamentals and applications. Chemical Reviews, 2022.
- Imdad Uddin Chowdhury, Pallab Sinha Mahapatra, Ashis Kumar Sen, Arvind Pattamatta, and Manish K. Tiwari. Autonomous transport and splitting of a droplet on an open surface. Physical Review Fluids, 2021.
- Subhashis Patari and Pallab Sinha Mahapatra. Liquid wicking in the paper strip: an experimental and numerical study. ACS Omega, 2020.
Energy & Thermal Management Applications
Energy and thermal management research translates interfacial transport and phase-change physics into compact cooling technologies. Battery thermal management is a major focus, spanning localized cold plates, graphite-assisted heat spreading, immersion cooling, infrared thermography, electrochemical-thermal modelling, and machine-learning-based temperature reconstruction for Li-ion pouch cells. We also develop pulsating and wickless heat pipes, flat thermosyphons, and vapor-chamber concepts that spread heat through evaporation, vapor transport, condensation, and passive liquid return. These approaches support efficient cooling of batteries, electronics, chips, and data-center hardware.
Battery thermal management
Localized cold plates, graphite heat spreaders, immersion cooling, and predictive thermal models for safer, more uniform Li-ion pouch-cell temperatures.
Battery cooling study (2026)Heat pipes
Pulsating and wickless heat pipes use two-phase oscillatory transport and engineered wetting surfaces for compact electronics cooling.
Pulsating heat-pipe study (2026)Thermosyphons & vapor chambers
Flat two-phase spreaders move heat through evaporation and condensation, enabling passive and energy-efficient chip-level thermal management.
Flat thermosyphon study- 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.
- 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.
- 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.
- Davis T Vempeny, Laxman Kumar Malla, Hemanth Dileep, Pallab Sinha Mahapatra, Pankaj Srivastava, and Arvind Pattamatta. A novel antiparallel flat plate pulsating heat pipe for thermal management of electronics. Experimental Heat Transfer, 2026.
- 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.
- 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.
- Laxman Kumar Malla, Praveen Dhanalakota, Hemanth Dileep, Pallab Sinha Mahapatra, and Arvind Pattamatta. Surface Wettability Modifications and Applications in Wickless Heat Pipes. Surfaces and Interfaces, 2024.
Collective & Active Matter
Collective and active matter research examines how local interactions produce organized behavior at larger scales. Microswimmer modeling resolves rheotaxis, confinement effects, thermal fluctuations, colloidal environments, and transport through complex channels. Our predator–prey studies investigate repeated attacks, escape responses, and the collective consequences of interaction rules. We also study active-passive mixtures, particle clouds, smart-particle mixing, segregation, and transitions between dynamical states. Simulations, theory, and data-driven strategies connect particle-scale activity to emergent motion and transport.
Microswimmer modeling
Mesoscale simulations examine rheotaxis, confinement, thermal fluctuations, colloidal loading, and swimmer transport in channel flows.
Microswimmer study (2026)Predator–prey dynamics
Interaction-based models reveal how prey respond to repeated attacks and how individual decisions shape collective survival dynamics.
Predator–prey studyActive matter
Active agents drive mixing, segregation, collective motion, and transitions between dynamical states in interacting particle systems.
Active-particle mixing study (2026)- Margam Ramprasad, Shubhadeep Mandal, and Pallab Sinha Mahapatra. Rheotaxis of microswimmer in colloid-laden channel flow. Physics of Fluids 38, 106801 (2026).
- Thomas Jacob, Siddhant Mohapatra, Rajalingam A., Sam Mathew, and Pallab Sinha Mahapatra. Mixing of a binary passive particle system using smart active particles. Scientific Reports, 2026.
- Siddhant Mohapatra and Pallab Sinha Mahapatra. Behavioural response of prey to repeated attacks by non-coordinating predators. Scientific Reports, 2025.
- 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.
- Naveen Kumar Agrawal and Pallab Sinha Mahapatra. Alignment-mediated segregation in an active-passive mixture. Physical Review E, 2021.
- Pallab Sinha Mahapatra, Ajinkya Kulkarni, Sam Mathew, Mahesh V. Panchagnula, and Srikanth Vedantam. Transitions between multiple dynamical states in a confined dense active-particle system. Physical Review E, 2017.