Microsystem technology is concerned with the development and manufacture of components with dimensions in the micrometre range. For this purpose, both classic and new procedures from the micro-technology sector are used.
When micro-mechanical or micro-optical elements are integrated with micro-electronic assemblies, we call these microsystems. Such microsystems contain structures that are much smaller than the diameter of a human hair.
Due to the trend in automation towards “smaller, faster, more intelligent”, innovative sensors and actuators play an important role for use in miniaturised and distributed control systems with integrated intelligence (smart systems). Smart systems reliably measure physical variables such as position, temperature, pressure, vibration and force.
They therefore provide operating parameters for production, support the quality assurance function or make it easier to maintain production facilities. The efficiency of these control systems is greater the more that physical variables can be measured by intelligent sensors. The processes and systems can be optimised by evaluating the data. This also results in the motivation to make sensors smaller, sturdier and more flexible. The methods of MST are predestined for this.
Micro valve technology
Familiar products based on micro electro mechanical systems (MEMS) can be found among other things in the field of dosing systems for liquids and other medical applications. Most of these valves are switched by an electrostatic or thermal drive. These drives are less reliable, however, and only reach limited strokes. For the construction of pneumatic valves with their typical high requirements for robustness and service life, other methods of micro technology and precision engineering this have to be used, which also meet the miniaturisation requirements for use in industrial automation.
The research at Festo is therefore also concerned with micro valves using piezo bending actuators or compact electromagnetic drives. In this respect, the focus is on the virtual layout and simulation (magnetic filed calculation or the behaviour of piezo benders) as well as on building prototypes.
Sensors provide important information for the operation of an automation system. For this purpose, measured values such as flow, pressure and position of drives must be recorded continuously with high accuracy.
In the research field, sensors with new functions are developed, which are aimed at promoting further miniaturisation by means of functional integration. For example, printed magnetic field sensors for measuring positions on pneumatic drives have been studied in research projects. Other research plans are occupied with flexible electronics in thin films, which, when applied to a gripper for example, enable the gripping power and object size to be determined. Printed electronic components for pressure or force sensors as well as wireless concepts for data transmission purposes are also the object of research work. Using the latest simulation technologies, research also makes an important contribution to the layout of sensor/magnet pairs for the design of future pneumatic drives.
Besides piezo and electromagnetic drives, new types of actuator in the form of electroactive polymers are also being investigated. These have performance characteristics similar to those of electromagnets. In principle these behave like piezo drives, which means they are very energy efficient, yet have a higher performance capability than piezo bending actuators.
At the moment, the disadvantage with electroactive polymers, which are produced in a stack construction, lies in the high supply voltage of around 2,000 to 3,000 volts. As part of funding projects, the research at Festo works on reducing this voltage in order to widen the application area for electroactive polymers.
Camera technology and image processing
Cameras are increasingly used in industry for production processes. The cameras are mostly used with so-called “grab from the conveyor” as well as in the quality checking of components and assemblies in order to record the objects.
In future, people will work together with machines much more in production. Camera technology, combined with appropriate image processing algorithms, is able to deliver critical added value for the human-machine interaction. The systems available on the market are thus being evaluated in research with regard to the human-technology interaction requirements and new camera systems are being developed with research partners. Algorithms must also be implemented, which improve the collaboration between humans and robots or make it possible in the first place.