Answer
The principle employed in scanned-probe microscopy is that of non-alteration of the specimen. The specimen being observed does not have to undergo any form of special preparation which would enable it to be observed. Further, the specimen can be observed in its natural environment, and does not need to be isolated in a semi-vacuum to be observed.
Work Step by Step
1. Traditional methods of microscopy require the specimen to be isolated in a semi-vacuum to be observed.
2. The preparation which this requires is time-consuming, and the data gleaned is imperfect as the specimen is not being naturally observed.
3. Scanning-probe microscopy gets around this problem by using electric current on the specimen surface in order to study it.
4. Doing this also allows a specimen to be observed within certain environments, giving a more accurate picture of its function.
5. The specimen does not have to undergo any alteration which may impair its physical integrity, allowing for a more accurate assessment of it.
