Pressure Sensing Strip for Rapid Aerodynamic Testing
Within the European project INTEGRAMplus a pressure sensing strip is being developed in order to measure pressure profiles for rapid aerodynamic testing. It combines state of the art pressure sensing technology with integrated micro-fluidic pressure signal guidance in order to produce a non-intrusive pressure distribution measurement device.
Currently low pressure profiles are primarily measured with pressure transducer arrays: A number of tubes lead from a pressure transducer array to corresponding measuring taps on the surface to be measured. Setting up such a system is time consuming and costly and on thin profiles or brittle materials it is not even an option (e.g. sails, glass). Alternatively, non intrusive pressure sensitive paints can be utilized, but they lack as far as sensitivity, accuracy and reproducibility is concerned.
A novel pressure sensing strip was developed which allows measuring pressure profiles non-intrusively without impeding sensitivity. The device can directly and easily be placed onto the surface to be measured. It combines state of the art pressure sensing technology (piezo-resistive sensors) with integrated microfluidic pressure signal guidance. A film with integrated micro-channels guides pressure signals from an arbitrary point on the surface to the sensor, which is placed away from sensitive pressure measurement locations not obstructing the fluid flow. To achieve this a face-up bonding process for MEMS devices on flexible prints based on silicone rubber was developed. The electrical contacts were provided by gold wire bonds.
Wireless data transmission can be utilized in order to further increase system flexibility such as mounting the entire device on a rotating blade (e.g. wind turbine).
Potential markets can particularly be found in R&D testing environments (e.g. wind tunnels) in following industries:
- Automotive
- Aerospace
- Wind turbines
- Urban goods
- Watercrafts
- HVAC
Table 1: Targeted specs
| Pressure range | 6000 | Pa |
| Pressure accuracy | 30 | Pa |
| Pressure resolution | 3 | Pa |
| Strip thickness (at measuring points) | < 0.3 | mm |
| Strip length | 20 to 500 | mm |
| Temperature range | 0 to 60 | °C |
| Measuring speed per sensor | 300 | Hz |
This work was supported by the EU, (project IST-FP6-027540, INTEGRAMplus) and the MCCS Micro Center Central Switzerland. We thank them for their support