An interesting niche in the mechatronic world is the laboratory automation market. Applications in this arena can be syringe dispensing of tiny volumes of fluids, automatic dispensing and sampling of chemicals, DNA processing and many other applications. For the most part, the applications are Cartesian arrays of samples in small wells and single or multiple dispensing devices on a moving head. The number of samples being managed can be anything from 1 to 96.
The motion is often powered with small stepping motors and a variety of mechanical solutions, some using timing belts and pulleys, some using lead screws, and some using rack and pinion acuation. It doesn’t look terribly difficult, but the fact is that as throughput demands increase, the motion is much more difficult. Components that are cantilevered tend to flex and oscillate which can disturb the accuracy of the motion or require settling time between motions.
There are no simple rules for the kinematics of these systems that will make them more efficient. Next generation throughput is going come with some R&D and increased hardware costs. And, next generation performance is going to require next generation design tools, which hopefully are on the near horizon.
The motion is not “mission critical” as it would be for a heart/lung machine or other system that involves risk to human life. So conventional controls are acceptable. But the emphasis of the equipment is the data that results from the processes. So a lot of care is taken to insure that the right data is associated with the right sample. A lot of money is spent on the PC software and hardware to make sure that the data is accurate.
The motion control aspect of this industry is not the primary focus of its engineering efforts. Some companies are already experiencing limits in what the hardware can do. So it remains, to get to the next performance plateau, we will need to throw out the handbook of how its been done up to now and start over with a clean sheet of paper.
As with most mechatronic applications, there has to be a change in the mechanical design of the system in order to achieve better throughput. What that change is, is not immediately obvious or someone would already be doing it. But that is how the progression takes place.
So we’ll stay involved in the industry and see how the next evolution takes place.
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