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Development of Micro-Valves for Pulsed Jet Actuators

: Lipowski, M.

Borgmann, Hubert ; Wirtschaftsförderung Bremen GmbH -WFB-:
Actuator 2014, 14th International Conference on New Actuators & 8th International Exhibition on Smart Actuators and Drive Systems. Conference Proceedings : 23-25 June 2014, Bremen, Germany
Bremen: Messe Bremen, 2014
ISBN: 978-3-933339-23-2 (CD-ROM)
ISBN: 978-3-933339-22-5 (Print)
ISBN: 978-3-933339-24-9 (Print + CD-ROM)
International Conference on New Actuators <14, 2014, Bremen>
International Exhibition on Smart Actuators and Drive Systems <8, 2014, Bremen>
Fraunhofer ENAS ()

Pulsed Jet Actuators (PJAs) are low-power, high-compacted micro fluidic devices which are used for different applications which require a pointed and pulsed air flow. The source of the airflow is a chamber filled with compressed air. The chambers` inlet is connected to an air supply and the outlet is formed as a nozzle. To achieve a pulsed air flow a valve is required which is located between the chamber inlet and outlet. The signal type of the valve is responsible for the airflow through the nozzle. Normally the valve is located on the inlet of the chamber and it is possible to use COTS valves (components of the shelf) to realize the Pulsed Jet conduction. This design has two big disadvantages. At first the huge space requirements are limiting the implementation of such constructions into relevant structures. Furthermore the chamber which distributes air to multiple outlets will have a significant pressure loss when minimizing it`s size to reduce the fluidic capacity and to fit in flat structures. Therefore a new valve solution and a new PJA design are required. The new valve design was developed based on the piezoelectric bender structures which are directly connected to the exit holes of the PJ chamber. This solution allows a direct switching of the air flow at the nozzle and as well as an optimized chamber design. The new design uses micro technology-based valve structures to create a pulsed air flow out of compressed air. The valve is located directly under the outlet (nozzle) to downsize the chamber size and fluidic capacities that may influence the pulsed signal. A schematic view of the system is shown in figure 1. The main purpose of this paper is to highlight the actuator requirements for an integrated system and to describe a solution that fits those needs. Additionally the focus is on the dimensioning of the bender elements with simultaneous consideration of mechanical as well as fluidic aspects.