RESUMEN
Here, we developed a novel and facile method to control the local water adhesion force of a thin and stretchable superhydrophobic polydimethylsiloxane (PDMS) substrate with micro-pillar arrays that allows the individual manipulation of droplet motions including moving, merging and mixing. When a vacuum pressure was applied below the PDMS substrate, a local dimple structure was formed and the water adhesion force of structure was significantly changed owing to the dynamically varied pillar density. With the help of the lowered water adhesion force and the slope angle of the formed dimple structure, the motion of individual water droplets could be precisely controlled, which facilitated the creation of a droplet-based microfluidic platform capable of a programmable manipulation of droplets. We showed that the platform could be used in newer and emerging microfluidic operations such as surface-enhanced Raman spectroscopy with extremely high sensing capability (10(-15) M) and in vitro small interfering RNA transfection with enhanced transfection efficiency of ~80%.
Asunto(s)
Técnicas Biosensibles/instrumentación , Dimetilpolisiloxanos/química , Microfluídica/instrumentación , Microfluídica/métodos , Micromanipulación/instrumentación , Agua/química , Adhesividad , Diseño de Equipo , Análisis de Falla de Equipo , Interacciones Hidrofóbicas e Hidrofílicas , Propiedades de Superficie , VacioRESUMEN
A flexible and sensitive textile-based pressure sensor is developed using highly conductive fibers coated with dielectric rubber materials. The pressure sensor exhibits superior sensitivity, very fast response time, and high stability, compared with previous textile-based pressure sensors. By using a weaving method, the pressure sensor can be applied to make smart gloves and clothes that can control machines wirelessly as human-machine interfaces.
