Valves stepper motor-driven

B, manifold-mounted valves arranged in banks of 3 C, integrated 750 /tL stepper motor driven syringe pump D, linear worm drive E, stirrer stepper motor F, pressure release and pump check valves G, external sample port and 10 cm scale. 

Integrated microfluidics comprising a system of valves (Fig. 2), channels and a detector chip are the core of Biospecific Interaction Analysis (BIA) systems developed and manufactured by Pharmacia Sweden [8,9,10]. From the viewpoint of total micro-miniaturization, BIA is a compromise, since it comprises micro- as well as macro- components. Stepper motor driven syringes (volume 500mL) are delivering the carrier stream of a... 

Central Electronics Engineering Research Institute, Pilani has developed an accurate and reliable microprocessor-based industrial grade 24-channel temperature controller (Micro-TEIMAC) which has been successfully field-tried in a few sugar factories of U.P. and Maharashtra. A unique feature of the Micro-TEIMAC system is the twenty-four channel controller. It provides 4-20 mA PID controller current output and helps in controlling the temperature of all the twenty-four channels automatically either with the help of stepper motor driven low torque valves or pneumatically controlled high torque valves and manually with the help of control status and deviation indicators by providing visual indication to the valve operator. In addition to this controller displays actual deviation of process temperature from set point in the form of bar graph for all 24-process points and has the facility to connect recorder to all points. 

A test system, controlled by personal computer (PC), was developed to evaluate the performance of the sensors. A schematic of this system is shown in Figure 3. The signals from the sensors were amplified by a multi-channel electrometer and acquired by a 16 bit analog to digital data acquisition board at a resolution of 0.0145 mV/bit. The test fixture provided the electrical and fluid interface to the sensor substrate. It contained channels which directed the sample, reference and calibrator solutions over the sensors. These channels combined down stream of the sensors to form the liquid junction as shown in Figure 1. Contact probes were used to make electrical connection to the substrate. Fluids were drawn through the test fixture by a peristaltic pump driven by a stepper motor and flow of the different fluids was controlled by the pinch valves. 

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