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Response Summary: Measuring force of tape removal

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  • Response Summary: Measuring force of tape removal

    Hi all,

    A big thank you to all responded to my question and my apologies for the
    delay in posting the summary. There were a variety of great suggestions and
    we are currently reviewing all options for best approach....

    Original Question:

    Dear Biomech-l Subscribers,

    We need to measure the force and angle applied by bandaid users to remove
    the adhesive from the skin. These must be real applications, not
    instron-type simulations. If needed, we have a motion capture system to get
    the angle measurements but are unsure what the best approach would be in
    measuring the force.  The first thought was to instrument the bandaid
    however there is concern that the rigidity of the sensor would affect the
    mechanics of removal since bandaids are pliable. It also has to be small
    enough that the mass will not have much of an effect. We've researched
    sensors and found a few possibilities but without first purchasing and
    trying them out it's hard to know what would work. Based on your
    experience, can anyone make recommendations on sensors and a possible
    approach? Any comments/suggestions are appreciated.


    Yvette Jones, MSc
    Research Associate
    British Columbia Institute of Technology
    Burnaby, British Columbia

    Summary of Responses

    Could you add a small tab to the band-aid which had a strain gauge or
    similar attached to it? I suspect you might have trouble fixing any sort of
    sensing element to the band-aid itself. How about using an instrumented
    pair of tweezers (or similar) to remove the band-aid?

    This reference may be useful to you ...

    Karwoski AC, Plaut RH. Experiments on peeling adhesive tapes from human
    forearms. Skin Res Technol 2004; 10:271-7

    Cormac Flynn, Auckland Bioengineering Institute,

    Can you do an in vivo test using an Instron-type machine?  You might
    build a seat to mechanically ground your subject with your tester.  You
    might need a pulley system to direct the pull of the tester.  When
    you're done making these things, you can set the rate of pull, the
    amount of pull, and the angle of pull.
    Your protocols should include orientation of the tape with respect to
    the skin tension lines, pre- and post-exfoliation, and any
    pre-conditioning of the skin or the tape.  I would be concerned about
    tests at a single site: how many tests can you perform on the same patch
    of skin within a given time frame?  What criteria do you use before
    testing again?
    You would want to do in vitro tests to understand the effect of tension
    on the tape (band-aid).
    I don't think size of the machine is an issue as compared to these other
    concerns.  However, after using the "Instron" to set up protocols and
    determine the operating ranges, then think about smaller testers.
    These are suggestions on my part.  Another suggestion is to contact Dr.
    Gary Grove at cyberDERM (  He has done or knows
    how to do mechanical and chemical testing on skin.  He may be able to
    advise you.
    Jim Furmato, TUSPM Gait Study Center

    Tough problem.  One approach to consider would be affixing (clamping,
    strapping?) the body part (digit?  limb?) to a force plate and isolating it
    from internal forces (that's the really tough part).  Then the force plate
    will record the magnitude and direction of force applied to the limb by the
    bandaid.  The isolation would probably have to include a combination of
    physical restraint of the more proximal body parts and instructions to
    relax.  May be worth a try, as I think it would be a lot simpler than
    instrumenting the bandaid, particularly when direction is a free variable
    that must be recorded, and you want a "natural" removal.
    Larry Abraham

    Why not use a strain gauged rod hooked or clamped into the end of the
    bandaid plaster and record the strain at multiple pulling angles.
    Dave Smith

    Interesting problem.  Does it have to be a human test?  The reason I ask
    is that it would be possible to measure the forces indirectly by using
    an animal model.  You could setup a piece of animal tissue, with the
    skin intact on a force plate or weigh scale and then remove the bandaid
    from the sample whilst it is on the scale.  The reduction in weight of
    the sample will correspond to the total force being exerted by the
    bandaid on the sample as it is removed. You can obviously film it
    simultaneously and then synchronize your video and force data using some
    common event.. say tapping the specimen prior to pulling the bandaid
    I suppose you could use a human cadaver if you need it to be as
    realistic as possible, but I suspect that the animal tissue would be a
    close approximation.
    Sean Osis, University of Calgary

    I developed a mathematical model to correct for hysteresis and creep, and a
    mechanical pre-loading procedure to eliminate shear loading effects on FSR
    semi-conductive polymer sensors (Interlink Electronics), to allow for
    accurate compressive force measurements (see attached).  By using the
    mathematical model and pre-loading procedure, you should be able to get
    accurate and reliable compressive force measurements in your bandaid study.
    I would recommend attaching a sensor to one end of the bandaid using a
    strong adhesive to prevent sliding. There is a technique described in the
    article for converting the sensor from a pressure-sensor to a force-sensor,
    followed by the pre-loading procedure to eliminate shear loading effects.
    Let me know if you have any questions regarding the mathematical model or
    pre-loading procedure used.
    Rick Hall

    I guess the answer to your force measurement query will depend on how much
    accuracy/precision is desirable in your application, how soon you want the
    results and how much you are ready to pay for all of it. Also, from your
    problem description below, I believe you want to compute the shear force
    (along the bandaid plane) between the thumb/index finger and the bandaid.
    We have used strain measurement devices from Vishay Precision Group ( on ligaments. Many
    investigators have used their strain gages on bones (tibia,
    anterior/lateral vertebral body, etc.) For your application, I guess you
    could use one of their low profile shear stress sensors (Transducer Class
    or Stress Analysis strain gages). However, you may have to buy their signal
    conditioning unit as well.
    A more fancy option could be their optical measurement option:  (
    I am not sure about the cost but time to start collecting data should be
    short in both cases.

    I recall from my tissue mechanics days that the way we measured strain in
    skin was to draw a grid on it then measure the distortion of the lines. I
    think this is probably the best approach for your problem. You would have
    to measure the Young's Modulus of the band-aid so that you can calculate
    stress from strain. As you say, any sensor will tend to distort the
    band-aid, and I think you will be hard pressed to find a suitable sensor
    anyway - Hall effect would probably be the only option, I guess.
    Chris Kirtley, Sole Health Care Products Pty Ltd

    There is a material called Quantum Tunnelling Composite manufactured by a
    company in the UK called Peratech. The material is piezoresistive, rubber
    like, and can be manufactured to almost any form. The material itself
    is effectively a pressure sensor, exhibiting a resistance of 10 kOhms under
    no load to under 1 Ohm under full load.