Abstract: A microstructured surface with microfeatures formed thereon and defining spaces between the microfeatures includes least one electrode of an electrode pair in the spaces, wherein electrodes of the pair are electrically connected to one another. The at least one electrode located in the space is configured to generate a gas in between the microfeatures when an electrolyte solution penetrates into the microfeatures. Importantly, the electrodes are not connected to any external power source. Because the microstructured surface is self-powered in replenishing the gas lost in a submerged condition, no additional provision to supply energy or regulate the replenishment is necessary for implementation and use.

Abstract: A method of making microstructures having re-entrant or doubly re-entrant topology includes forming a mold defining the negative surface features of the re-entrant or doubly re-entrant topology that is to be formed. In one embodiment, a soft or flowable material is formed on a first substrate and the mold is contacted with the same to form a solid, now positive surface having the re-entrant or doubly re-entrant topology. The mold is then released from the first substrate. The microstructures are secured to a second, different substrate, and the first substrate is removed. Any residual microstructure material located between adjacent microstructures may be removed to form the separate microstructures on the second substrate. The second substrate may be thin and flexible any manipulated into useful or desired shapes having the microstructures on one side thereof.

Abstract: A microstructured surface with microfeatures formed thereon and defining spaces between the microfeatures includes least one electrode of an electrode pair in the spaces, wherein electrodes of the pair are electrically connected to one another. The at least one electrode located in the space is configured to generate a gas in between the microfeatures when an electrolyte solution penetrates into the microfeatures. Importantly, the electrodes are not connected to any external power source. Because the microstructured surface is self-powered in replenishing the gas lost in a submerged condition, no additional provision to supply energy or regulate the replenishment is necessary for implementation and use.

Abstract: A low-profile shear-sensing unit includes a floating plate surrounded by a frame and a displacement sensor that measures in-plane movement of the floating plate. Covered with a surface sample, the floating plate is displaced by the friction drag (i.e., shear) on the surface caused by the flow of fluid and the in-plane displacement is measured by the displacement sensor. The shear force on the sample surface is then obtained by multiplying the measured displacement and the spring constant of the flexure beams, which suspend the floating plate. The floating plate and the flexure beams are formed out of one plate or substrate to achieve monolithic construction with a beam geometry that leads to a high-resolution measurement.

Abstract: A method of making microstructures having re-entrant or doubly re-entrant topology includes forming a mold defining the negative surface features of the re-entrant or doubly re-entrant topology that is to be formed. In one embodiment, a soft or flowable material is formed on a first substrate and the mold is contacted with the same to form a solid, now positive surface having the re-entrant or doubly re-entrant topology. The mold is then released from the first substrate. The microstructures are secured to a second, different substrate, and the first substrate is removed. Any residual microstructure material located between adjacent microstructures may be removed to form the separate microstructures on the second substrate. The second substrate may be thin and flexible any manipulated into useful or desired shapes having the microstructures on one side thereof.

Abstract: A low-profile shear-sensing unit includes a floating plate surrounded by a frame and a displacement sensor that measures in-plane movement of the floating plate. Covered with a surface sample, the floating plate is displaced by the friction drag (i.e., shear) on the surface caused by the flow of fluid and the in-plane displacement is measured by the displacement sensor. The shear force on the sample surface is then obtained by multiplying the measured displacement and the spring constant of the flexure beams, which suspend the floating plate. The floating plate and the flexure beams are formed out of one plate or substrate to achieve monolithic construction with a beam geometry that leads to a high-resolution measurement.