Mar 29, 2016 | 1 Comment | By Andrew Robinson
1.) With Todd’s help, we have purchased an amplifier. We purchased the PD200 amplifier from PiezoDrive. It has a specific mode designed for pulse drive of actuators (primarily for valve actuation applications). This mode can go up to 10A so when paired to a low capacitance actuator, we should be able to get response times <20 microseconds.
3.) The amplifier works off of an input signal generator. I am currently working on looking around for a signal generator that we could take to APS and can generate pulses on a microsecond level with microsecond triggering. I haven’t found one in the Latrobe lab yet, so if anyone knows where one is I would appreciate the info. Also, I suspect Mark Foster’s lab may have something we could use, so the next plan is to ask their lab for some advice on signal generators, and at best loan one from them.
2.) We are planning on ordering the PPA20M actuators. They have a rated max displacement of 20 micron nominal (down to 17, and up to 28). With a blocking force added, the displacement goes down slightly, but because our system is so small, it likely won’t exert more than 10 N based on Abaqus (this could be slightly more or less depending on how well the notch cutting goes with the diamond wire).
3.) Cutting notches with the diamond wire into the samples is hard to do accurately for the small 4mm long samples.
We can adjust the stage only in one direction precisely. This is the direction that determines how centered the notch is on the beam (i.e. for the 4mm long beam sample, we want it at 2mm across). Currently the depth of the notches is controlled by hand. The samples are unmounted, viewed in the microscope, then remounted, and this process is repeated until the depth is as close as possible to the specified 200 micron depth.
Since there are some chips forming at the tip of the notch as the diamond wire advances. We are working on getting some better pictures/characterization of these chips in the SEM.