A5021530380- Surface Modification and Superhydrophobicity
- Fluid Dynamics and Heat Transfer
- Micro and Nano Robotics
- Adhesion, Friction, and Surface Interactions
- Modular Robots and Swarm Intelligence
- COVID-19 and healthcare impacts
- Infection Control and Ventilation
- Pickering emulsions and particle stabilization
- Refrigeration and Air Conditioning Technologies
- Advanced Sensor and Energy Harvesting Materials
- Climate Change and Health Impacts
- Bone and Dental Protein Studies
- Nanomaterials and Printing Technologies
- Mechanical Failure Analysis and Simulation
- Fluid Dynamics and Thin Films
- Mass Spectrometry Techniques and Applications
- Icing and De-icing Technologies
- Advanced Materials and Mechanics
- Polymer composites and self-healing
- Salivary Gland Disorders and Functions
- Perovskite Materials and Applications
- Engineering Applied Research
- Electrohydrodynamics and Fluid Dynamics
- Plant Surface Properties and Treatments
- Fibroblast Growth Factor Research
Nanyang Technological University
2020-2024
King Abdullah University of Science and Technology
2023-2024
Meharry Medical College
2008
Achieving programmable and reversible deformations of soft materials is a long-standing goal for various applications in robotics, flexible electronics many other fields. Swelling-induced shape morphing has been intensively studied as one the potential mechanisms. However, achieving an extremely large swelling ratio (>1000% volume) remains challenging with existing swellable (e.g., hydrogels water-swellable rubbers). Inspired by change enabled osmosis-driven living organisms, herein, we...
Recently, there is much interest in droplet condensation on soft or liquid liquidlike substrates. Droplets can deform and interfaces resulting a wealth of phenomena not observed hard, solid surfaces (e.g., increased nucleation, interdroplet attraction). Here, we describe unique collective motion condensate water droplets that emerges spontaneously when substrate covered with thin oil film. move first serpentine, self-avoiding fashion before transitioning to circular motions. We show this...
Facing shortages of personal protective equipment, some clinicians have advocated the use barrier enclosures (typically mounted over head, with and without suction) to contain aerosol emissions from coronavirus disease 2019 (COVID-19) patients. There is, however, little evidence for its usefulness. To test effectiveness such a device, we built manikin that can expire micron-sized aerosols at flow rates close physiological conditions. We then placed inside enclosure used laser sheet visualize...
A water droplet can bounce off superhydrophobic surfaces multiple times before coming to a stop. The energy loss for such rebounds be quantified by the ratio of rebound speed UR and initial impact UI; i.e., its restitution coefficient e = UR/UI. Despite much work in this area, mechanistic explanation rebounding droplets is still lacking. Here, we measured submillimeter- millimeter-sized impacting two different over wide range UI (4-700 cm s-1). We proposed simple scaling laws explain...
<title>Abstract</title> Previously, we and others have used cantilever-based techniques to measure droplet friction on various surfaces, but typically at low speeds <italic>U</italic> < 1 mm s<sup>-1</sup>; higher speeds, measurements become inaccurate because of ringing artefacts. Here, are able eliminate the noise using a critically damped cantilever. We measured superhydrophobic surface over wide range = 10<sup>−5</sup>– 10<sup>−1</sup> m s<sup>−1</sup> identified two regimes...
<title>Abstract</title> Traditionally, investigations of Coulomb explosions have focused on charged microdrops levitated using quadrupole electric fields, i.e., a Paul trap. In surprising twist, our work introduces simple method to observe explosions, with no drop levitation and external field. Instead, we generate water conventional micropipette, which then deposit plastic petri dish lubricated thin oil film. As the droplet evaporates, its radius shrinks until it reaches Rayleigh limit at...
Previously, we and others have used cantilever-based techniques to measure droplet friction on various surfaces, but typically at low speeds
This paper is associated with a video winner of 2023 American Physical Society's Division Fluid Dynamics (DFD) Gallery Motion Award for work presented at the DFD Motion. The original available online Motion, Published by Society 2024
Viscous droplets impinging on soft substrates may exhibit several distinct behaviours including repeated bouncing, wetting, and hovering, i.e., spreading retracting after impact without bouncing back or wetting. We experimentally study the conditions enabling these characteristic by systematically varying substrate elasticity, velocity liquid viscosity. For each transition to wetting is determined as dependence of Weber number We, which measures droplet's kinetic energy against its surface...
Abstract Facing shortages of personal protective equipment, some clinicians have advocated the use barrier enclosures (typically mounted over head, with and without suction) to contain aerosol emissions from coronavirus disease 2019 (COVID-19) patients. There is however little evidence for its usefulness. To test effectiveness such a device, we built manikin that can expire micron-sized aerosols at flow rates close physiological conditions. We then placed inside enclosure used laser sheet...
Recently, there is much interest in droplet condensation on soft or liquid/liquid-like substrates. Droplets can deform and liquid interfaces resulting a wealth of phenomena not observed hard, solid surfaces (e.g., increased nucleation, inter-droplet attraction). Here, we describe unique complex collective motion condensate water droplets that emerges spontaneously when substrate covered with thin oil film. move first serpentine, self-avoiding fashion before transitioning to circular motions....
Abstract Recently, there is much interest in droplet condensation on soft or liquid/liquid-like substrates. Droplets can deform and liquid interfaces resulting a wealth of phenomena not observed hard, solid surfaces (e.g., increased nucleation, inter-droplet attraction). Here, we describe unique complex collective motion condensate water droplets that emerges spontaneously when substrate covered with thin oil film. move first serpentine, self-avoiding fashion before transitioning to circular...
Viscous droplets impinging on soft substrates may exhibit several distinct behaviours including repeated bouncing, wetting, and hovering, i.e., spreading retracting after impact without bouncing back or wetting. We experimentally study the conditions enabling these characteristic by systematically varying substrate elasticity, velocity liquid viscosity. For each transition to wetting is determined as dependence of Weber number We, which measures droplet's kinetic energy against its surface...
From hydrogels and plastics to liquid crystals, soft solids cover a wide array of synthetic biological materials that play key enabling roles in advanced technologies such as 3D printing, robotics, wearable electronics, self-assembly, bioartificial tissues. Their elasticity stimuli-induced changes mechanical, optical, or electrical properties offer unique advantage designing creating new dynamically functional components for sensing, micro-actuation, colour changes, information, mass...