Micro-scale biochemical reactors have been developed from a polydimethylsiloxane/enzyme (PDMS-E)biopolymer. Micro-reactor channels 125 micrometers in depth, 500 micrometers wide by 50 centimeters long contain fixed triangular features for enhanced fluid mixing. All channel features are composed of the same PDMS-E material. Conversions of urea by urease enzyme of up to 70% have been obtained at an overall flowrate of 0.4 mL/min. Additional PDMS-E biopolymer systems containing amyloglucosidase (for converting starch to glucose) have demonstrated enzymatic activity.
Study of an aqueous-phase reaction in an enzyme- catalyzedpolydimethylsiloxane (PDMS) microreactor is underway. In the present work, urease - an enzyme that catalyzes urea to ammonia and carbon dioxide has been immobilized within open microchannels of 450 micrometers (micrometers ) in diameter or less. Microchannels are templated within PDMS. Preliminary results demonstrate the proof of concept for conversion biochemicals via a PDMS-based microreactor system.
An experimental system has been designed and constructed to conduct gas- solid heterogeneous catalytic reactions in microreactors. This apparatus is inteded to be used for any exothermic or endothermic reaction, including those with multiple feeds. It can be used to test the effectiveness of a microreactor design for a particular catalyst or to test the behavior of the catalyst itself. The system uses a test block that is plumbed for multiple feeds and vacuum to hold down a standard size microreactor chip. This chip has two exit vias, which includes one for the reactor effluent and one for the exit stream from a possible reactor membrane wall. The reactors are systems of channels with a smallest cross-dimension as small as 5 micrometers. The experimental system is equipped with temperature control and automatic data acquisition. The reactors can be stacked in order to scale up to higher throughput. A simulator has been developed that accounts for the unique physical aspects of reaction and flow in very small channels. Along with design, it assist in determining operating conditions and interpreting experimental results.