English: A diagram showing the operation of a slip-stick piezoelectric actuator, providing coarse and fine positioning modes. Coarse positioning provides long range but low precision, while fine positioning provides high precision and short range. The slip-stick principle: Slow actuation of the piezo element leads to fine positioning. A combination of rapid contraction and slow extension can make the actuator move in coarse steps Δx because the force on the base becomes larger than the static friction force between the base and base plate. Reversing the direction is done by using slow contractions instead.