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Piezoelectric effect- tube scanner

  1. Oct 8, 2013 #1

    i have been working on this problem for a while. i just need some guidance.

    the question is: design a ztube scanner suitable for displacing ±1 micron displacement at 200V.

    i am using this equation:

    ΔL=(d31 ×L×V)/t

    ΔL=change in length = 1micron
    d31=piezo strain constant (usually in pico range [10]^{}[/-12]
    V=applied voltage
    t=thickness (for a tube-- Outer diameter - inner diameter (OD-ID))

    Rearranging the equation:


    ΔL/V= L/(d×d31)


    Im currently using this link.

    I am trying to solve it by,
    choosing V=200V
    ΔL= 1micron


    how do i proceed after this step? i tried picking a value for [d]_{}[/31]=1.27[10]^{}[/-12]
    but then i got stuck on picking realistic diameters for the piezo tube.

    I am also wondering is the d31 chosen arbitrary, or its specific to the material being used, and so is it a parameter i cant control in the equation.
    Usually d31 is given in pico scale.
    Max diameter__ OD=78mm, ID=70mm
    MIn diameter__ OD=2mm, ID0.8mm
    d31= ?

    i might be missunderstanding the question or equation.

  2. jcsd
  3. Oct 8, 2013 #2


    User Avatar
    Science Advisor
    Gold Member

    d31 (and d33) are material parameters. You have to know the value for the material that you are using.
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