Transforming Precision Instrumentation: Active Vibration Control Enhances Pneumatic Isolation Systems

Typical applications for pneumatic isolation are things like high magnification optical microscopes, atomic force, and confocal microscopy applications like electrophysiology and other other techniques used in life science research. And a good example of that is TMC's clean bench table and micro g isolators. So this is a pneumatic isolator. It's about one and a half to two hertz resonant frequency, and the table is supported by these springs and is fairly soft. If there was a moving stage on top of the payload, the the payload would deflect. And it would it would bounce around a little bit before it settles down. So taking some of these advanced features that are coupled with a a pneumatic system and taking that to the next step would be something known as a parallel type active vibration control system. And in this system, we start with a pneumatic isolator, we have non contacting electro pneumatic pipe control. We include the active damping of the payload, but we also add linear motors. As an actuator. And when this is combined in a feedback system, it is very good at canceling stage motion. So it's a very high performance system it's a bit complex, certainly more more involved in in the setup and initial tuning, but it's very, very good for supporting payloads and have a moving stage. When the stage moves, a pneumatic spring would normally deflect pretty easily. But by adding the linear motor, in parallel with the with the pneumatic spring as part of a feedback system, it is setting a force to the payload to cancel the deflection of that payload. It can also one of the other nice things about this type of system is that it can be connected to the to the stage of of the tool, and information from that stage can be used in a feed forward manner to even more aggressively cancel that stage motion. Now is this an active vibration control system? It sure is. No doubt. But in terms of vibration isolation of the floor, it's really defined by the the spring that's being used. So if it's a pneumatic ice layer, which is common, could also be a steel spring or even a rubber mount, but this stiffer the spring, the less impact the the the the motor has. But in terms of floor vibration isolation, it's really defined by that that that spring. So in this design, these these add ons such as the linear motor, the act of dampening, It's all working to either cancel the stage motion or reduce the amplification at the resonant frequency of the air spring. So the attenuation of floor vibration is not necessarily improved. Slightly, particularly, again, at the amplification or, excuse me, at the resonant frequency of the isolator, but not beyond that. So it's a very it's very limited in terms of bandwidth for floor vibration.