Dependence of capillary forces on relative humidity and the surface properties of femtosecond laser micromachined titanium

Evaluation of the Electrowetting Effect on the Interfacial Mechanics between Human Corneocytes and Nanoasperities

“…It is known at the macroscale that applying an electric field to a droplet of water resting on a dielectric layer causes the contact angle of the droplet to decrease. At the micro- and nanometer scale, humidity in the air causes water to condense and form capillary bridges at contacting asperities within a solid–solid interface, which contributes to the overall adhesion and friction within the interface. − Many studies have previously shown that the friction at a skin–solid interface highly depends on the humidity by hydrating and softening the skin surface, increasing adhesion via capillary bridges, and/or lubricating the contact at very high humidity. , However, it is unclear what the relative effects of each mechanism are, and it is further unclear what effect, if any, electrowetting would have in such systems. While previous AFM studies have investigated electrowetting on dielectrics, the results are not quantitative and do not isolate electrowetting effects from electroadhesion and capacitive effects between the AFM tip and sample. , There is thus a need to develop an AFM technique that can effectively isolate the electrowetting effect from the myriad of other occurring effects, in order to better understand how electrowetting impacts adhesion and friction in electroadhesive haptic devices and ultimately engineer systems with higher sensitivity and more robust operation.…”

Photo Initiated Chemical Vapour Deposition To Increase Polymer Hydrophobicity

“…Advantages of physical treatment include basic processing and commercial accessibility 15 16 . To modify surfaces physically, several approaches are available such as electrospinning 17 , laser and chemical etching 18 19 20 21 methods. Solvent treatments can also be used to physically alter a surface, by depositing new groups on the surface and forming superhydrophobic microstructures.…”

Influence of Relative Humidity on Interparticle Capillary Adhesion

“…A number of advanced instruments are capable of quantifying adhesion, namely, surface force apparatus (SFA), force feedback microscope, force traction device, and atomic force microscope. , AFM is by far the most prevailing technique to investigate nano- to pico-Newton range forces with nanometer actuation displacement and is apt to measure the “pull-off” force or the critical tensile load to detach two adhered bodies such as a particle on a substrate. Equipped with an environmental chamber, adhesion in moist air can be accurately measured in systems such as microparticles on an oxide surface, atomic force microscope tip interaction with a smooth or patterned surface, pollen on hydrophilic surfaces, and micro-/nanoparticle interactions. , Despite the wide applications, AFM is limited to probes with nanoscale dimensions. Governed by similar working principles, SFA measures the intersurface interaction force between the two approaching atomically smooth cylindrical surfaces by detecting the deflection of a cantilevered spring attached to one of the cylinders.…”

“…13,14 AFM is by far the most prevailing technique to investigate nano-to pico-Newton range forces with nanometer actuation displacement and is apt to measure the "pull-off" force or the critical tensile load to detach two adhered bodies such as a particle on a substrate. Equipped with an environmental chamber, adhesion in moist air can be accurately measured in systems such as microparticles on an oxide surface, 15 atomic force microscope tip interaction with a smooth 16 or patterned surface, 17 pollen on hydrophilic surfaces, 18 and micro-/nanoparticle interactions. 19,20 Despite the wide applications, AFM is limited to probes with nanoscale dimensions.…”