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Modeling the in vivo microenvironment typically involves placing cells in a three-dimensional (3D) extracellular matrix (ECM) in physiologically relevant context with respect to other cells. The mechanical and chemical features of 3D microenvironments play important roles in tissue engineering, tumor growth and metastasis, and in defining stem cell niches,(More)
We consider the equilibrium flotation of a two-dimensional cylinder and a sphere at an interface between two fluids. We give conditions on the density and radius of these objects for them to be able to float at the interface and discuss the role played by the contact angle in determining these conditions. For cylinders with a small radius, we find that the(More)
We study the sinking of a dense cylinder initially supported horizontally at an air-water interface and then released. The sinking motion is studied experimentally and agrees quantitatively with a simple hydrodynamic model of the process. In particular, our model predicts that the time taken for the cylinder to become immersed in the liquid should be tsink(More)
A liquid drop that partially wets a solid surface will slide down the plane when it is tilted beyond a critical inclination. Here we report the study of the sliding velocity of such a drop. Experiments for measuring the steady sliding velocity of different liquids of drops are performed. We then construct a scaling law that predicts the sliding velocity(More)
This paper describes the locomotion of a water jumping robot which emulates the ability of the water strider and the fishing spider to jump on the water surface. While previous studies of the robots mimicking aquatic arthropods were focused on recreating their horizontal skating motions, here we aim to achieve a vertical jumping motion. The robot jumps by(More)
The capillary burst microvalve offers an attractive means to regulate microliquid flow owing to its simple structure and operation process. However, there existed no rigorous theoretical work to elucidate how the valve works and consequently to predict the valve-bursting condition. Therefore, here we report the theoretical investigation of how the capillary(More)
Although ultrasonic technology has been successfully adopted for semiconductor cleaning, a recent trend of extreme miniaturization of patterns calls for a novel process that can remove contaminant particles without damaging nanoscale patterns. Unstable bubble oscillations have been hypothesized to cause such surface damages, and here we show direct(More)
Accumulating evidence suggests that HtrA1 (high-temperature requirement A1) is involved in modulating crucial cellular processes and implicated in life-threatening diseases, such as cancer and neuropathological disorders; however, the exact functions of this protease in vivo remain unknown. Here, we show that loss of HtrA1 function increases fibroblast(More)
Harvesting water from humid air via dewing can provide a viable solution to a water shortage problem where liquid-phase water is not available. Here we experimentally quantify the effects of wettability and geometry of the condensation substrate on the water harvest efficiency. Uniformly hydrophilic surfaces are found to exhibit higher rates of water(More)
Technologies to harvest electrical energy from wind have vast potentials because wind is one of the cleanest and most sustainable energy sources that nature provides. Here we propose a flutter-driven triboelectric generator that uses contact electrification caused by the self-sustained oscillation of flags. We study the coupled interaction between a(More)