subatomic nano positioning flexure stage
· research, electronics
For my senior design project, Im working on developing the mechatronics for a really high precision positioning stage. The idea of the project is to study the parasitic dynamic errors that occur in these really high precision flexure stages. In order to do that, however, we needed a stage to test with.
The lab had an extra lion precision capacitance gage system that we were able to use for testing, along with an extra piezo driver. So for actuation, we used a PZT stack actuator and closed the loop with said capacitance gage. The control system basically just consisted of a PI controller, running at around 50 kHz with an ADS8681 16 bit ADC and a Pmod DA3 DAC. After calibrating the capacitance gage with the shop Agilent interferometer, I found the system to have a per-bit resolution of around 300 picometers!
isolating its environment and analyzing the system at rest showed around +/-600 pm positioning accuracy, obviously making the large assumption there are no changes occuring between the nominal capacitance probe and carriage face distance :)
I think this qualifies as a nano positioning stage. The next plan is to develop the parasitic motion sensing system, now that this works.