B7.3 - Instrinsic Flow Control of a Piezo Membrane Pump
- SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
- Proceedings SENSOR 2011
- B7 - Actuators
- S. Dahms, J. Uckelmann, U. Michelsen - Bartels Mikrotechnik GmbH, Dortmund (Germany)
- 334 - 336
The market for micropumps is steadily emerging especially in the field of medical products. In some applications however membrane type pumps suffer from flow rate dependency on backpressure for example. This disadvantage can be overcome by implementing flow control. While a few approaches with off the shelf micropumps and flow sensors have been demonstrated, up to now no controlled-loop system with a fully integrated flow sensor is on the market.
Here an innovative approach is presented using the pump itself for flow control by generating and analysing feedback signals from the pump actuators. Therefore no additional flow sensor needs to be combined with the pump which lowers system complexity. Active component of the system is a piezo driven micropump with a size of about 30 x 15 x 3,8 mm³. As the piezo effect is reversible, it can not only be used for actuation but also for sensing. An optimized algorithm allows the implementation without a significant drop of pump performance.
Up to now, a flow range of 500 – 5000 μl/min by continuous pumping has been demonstrated with an accuracy of 10%. Further characterizations according to the IEC 60601-2-24 standard for the accuracy of infusion systems have shown that improved stabilization phases and accuracies in the order of available portable infusion systems can be achieved using the intrinsic flow control mechanism.