drifting of deflection recording during stress relaxation phase in force scripting

Alperen Ketene posted on Thu, Mar 3 2011 2:36 PM

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Hello,

I've been running into an issue recently while performing my usual stress relaxation response tests on di3100 afm on live cells. I set my force script to move my z-scanner about 1.5 um into my sample, forcing indentation and causing about 150nm deflection in my cantilever, and then hold the z-scanner position constant for 60s before i retract from the sample. The problem is that i see a gradual deflection increase after about 15 seconds during my stress relaxation phase and keeps increasing. I'm suspecting a drift in my laser but the fact is that i've always been doing the same script procedure. Does anyone have any clues as to why this is happening?

For reference, i'm using a triangular shaped cantilever(k=0.02 N/m) at sum values of 3.5-3.9.

Thanks.