If you need a scanner with precise nanopositioning, you may need to opt for one with piezo technology. However, before you jump in and make your final purchase, you may want to know what advantages are offered by piezo systems.
1. What is the piezo effect?
When you hear about piezo scanners, systems, stages, actuators and other devices, that is referring to items with a piezoelectric effect. This happens with a range of materials including quartz, and it simply means that the materials generate an alternating current when the exposed to vibration. This can be useful in items from microscopes to scanners.
2. How does the piezo effect help with nanopositioning?
In a piezo scanner, the piezo effect is harnessed in such a way that the elements of the scanner can make very small, very precise movements. The changing voltage of the materials facilitates these little moves in ways that mechanical devices would not be able to. These movements are significantly smaller than millimeters—1 million nanometers makes one centimeter.
3. How do piezo systems safeguard against error?
In most piezo scanners, the materials have very little friction between them. The elimination of friction prevents the parts from rubbing against one another and creating mistakes in the scan. Additionally, piezo systems have high levels of stiffness and low inertia. This allows them to be very responsive while working. Even if the parts are moving, they can stop and settle themselves in milliseconds or even microseconds with some machines. These tiny little pieces of time can vastly improve accuracy. In contrast, if piezo systems had high inertia, they would take longer to stop, and that could lead to errors.
When looking at different piezo scanners, look at the working ranges, number of linear axles and positioning resolution. The positioning resolution gives you an overall idea of the accuracy you can expect. In addition, if the scanner has linear axes with full rotary ability, that increases the range of movement, which also helps to prevent errors.
4. What about outside interference?
In some cases, the noises outside the scanner can affect the accuracy of the work. In particular, lots of noise can affect the system. However, you can mitigate this issue by choosing a piezo system with a high natural frequency. This increases the integrity of the scanner, and it prevents outside noises from affecting your design.
5. How do parallel kinematics help?
In many piezo scanners, the parts are set up in a parallel kinematic design. This simply means that all the platforms are stacked on top of each other in a parallel design. This is a relatively compact strategy, and it ensures wires or cables don't get int the way of the scanning process. Additionally, the low mass of the design makes it easier to move with relatively low voltages.
6. Do piezo systems last?
Finally, you may want to consider the lifespan of the piezo scanner before you buy it. Luckily, most piezo systems, and piezo ceramics in particular tend to have a relatively long lifespan. This cuts down on expense repairs and replacements, and ultimately, that can save you money in the long run. However, your system is likely to last even longer with a closed loop.
7. What are the advantages of closed-loop systems?
Finally, when looking for a nanoprecision scanner with piezo elements, you may also want to consider a closed-loop system. This helps to prevent dirt or debris from getting into the equipment. In addition, it also helps to boost precision, and it is especially useful if you create products that demand a lot of repetitive designs.