PDMS membrane-based microvalves are becoming increasingly more important for the control of fluid flow within MECS applications such as microreactors used to synthesize nanoparticles and biological macromolecules. The motivation for pursuing PDMS membrane-based microvalves is for implementing a plug flow microreactor to simulate slug flow yielding a narrower residence time...
The objective of this paper is to demonstrate a method for mechanically characterizing a 25 μm thick elastoviscoplastic hemodialysis membrane and for quantifying the force required to use that membrane in compression sealing. First, methods are developed for mechanically characterizing the thin elastoviscoplastic membrane. Then, a finite element model is...
More than 1.2 million people worldwide require regular hemodialysis therapy to treat end stage renal failure. In the United States alone, there are 300,000 patients and the National Kidney Foundation predicts that this number will double in the next 10 years. Currently most dialysis patients receive treatment at a dialysis...
Transient liquid-phase diffusion brazing is used in precision, hermetic joining applications as a replacement for diffusion bonding to reduce cycle times, reduce bonding pressure and improve yields. Studies showed that the interlayer used in diffusion brazing can be detrimental due to the use of melting point depressants (MPDs). The goal...
This thesis presents a novel microlamination architecture that enables the large scale integration of valves into low cost micro energy and chemical systems via membrane entrapment. Polycarbonate layers embossed with microfluidic channels were bonded by ultrasonic welding of raised embossed protrusions that penetrate though the PDMS membranes. The bonding pressure...
A low-temperature liquid-to-vapor counterflow microchannel heat exchanger has been redesigned and fabricated using a scalable, low-cost adhesive bonding process. Adhesive erosion concerns are mitigated with the use of sealing bosses. Performance has been tested using water and compressed air as test fluids. Results show greater effectiveness and higher heat transfer...
Almost 600,000 people in the United States were treated for End Stage Renal Disease in 2010. A majority of those people received hemodialysis from central medical facilities. It has been reported a better treatment option for these patients would be realized if the patients had more frequent hemodialysis treatments. A...
A new adhesive bonding method is introduced for microlamination architectures, for producing low-temperature microchannel arrays in a wide variety of metals. Sheet metal embossing and chemical etching processes have been used to produce sealing bosses and flow features, resulting in approximately 50% fewer laminae over traditional methods. These lamina designs...
Heating, ventilation, and air conditioning systems represent nearly half of building energy usage in the United States. Recent building regulations requiring increased air turnover within buildings will result in even greater air conditioning usage. To alleviate these concerns, membrane-based heat-and-moisture exchangers known as energy recovery ventilators have been developed to...