A peristaltic micropump was fabricated and characterized. The micropump was fabricated using soft lithography, and actuated using piezoelectric bimorph cantilevers. The micropump channel was formed by bonding two layers of PDMS, mixed at 5:1 and 30:1 ratios. The channel was fabricated in the 5:1 layer using replica molding (REM), where a very simple and inexpensive template was made by straddli...

The direct preparation of thermoresponsive monolithic copolymers by photopatterning of a liquid phase consisting of an aqueous solution of N-isopropylacrylamide, N-ethylacrylamide, N,N'-methylenebisacrylamide, and 4,4'-azobis(4-cyanovaleric acid) has been studied and the products used as valves within the channels of microfluidic devices. The volume change associated with the polymer phase tran...

New concepts for an impact actuated micro shift valve are presented which are useful e.g. as implant for the hydrocephalus disease. Such an implant must fulfil requirements, such as using biocompatible materials, a separation of the actuator from the fluid, MRT safety and low energy consumption in order to allow a battery powered system. The concepts are based on impacts that transmit an impuls...

This article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. The electrostatic actuation was induced by applying AC-DC voltage between the microbeam and electrode plate. In contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. In additio...

This paper describes electrically-activated fluidic valves that operate based on electrowetting through textiles. The valves are fabricated from electrically conductive, insulated, hydrophobic textiles, but the concept can be extended to other porous materials. When the valve is closed, the liquid cannot pass through the hydrophobic textile. Upon application of a potential (in the range of 100-...

Technologies for fabricating silicone rubber membranes and integrating them with other processes on silicon wafers have been developed. Silicone rubber has been found to have exceptional mechanical properties including low modulus, high elongation, and good sealing. Thermopneumatically actuated, normally open, silicone rubber membrane valves with optimized components have been designed, fabrica...

Multilayer soft lithography (MSL) is used to fabricate monolithic elastomeric on-off microvalves by adopting a two-layer cross-channel architecture. The performance of microvalves is strongly dependent on the two-channel geometry (width, height and shape) and on the thickness of the interlayer membrane. Using a finite element model previously validated against experiments, we propose a new flui...

BACKGROUND Presence of a tracheostomy tube often decreases the patient's ability to communicate and to tolerate oral intake. The initial tracheostomy tube change is often recommended between day 7 and 14 post insertion. Local guidelines permit tracheostomy tube change 5 days after insertion. OBJECTIVE We hypothesized that changing tracheostomy tubes before day 7 is associated with earlier use...