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{Prequel update:  the UW press team produced a nice version of this story that is a little less technical}

http://www.washington.edu/news/2015/02/09/3-d-printing-with-custom-molecules-creates-low-cost-mechanical-sensor/

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We would like to take a moment to share with you some very exciting news on our research front.    When different research teams partner together amazing things can and do happen.    This research paper is available free for about a year compliments of A.J. Boydston.     Click on the paper title below to read the paper.

We promise more AM related details and results soon.

3D-Printed Mechanochromic Materials

Department of Chemistry and Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 United States
ACS Appl. Mater. Interfaces, 2015, 7 (1), pp 577–583
DOI: 10.1021/am506745m
Abstract
We describe the preparation and characterization of photo- and mechanochromic 3D-printed structures using a commercial fused filament fabrication printer. Three spiropyran-containing poly(ε-caprolactone) (PCL) polymers were each filamentized and used to print single- and multicomponent tensile testing specimens that would be difficult, if not impossible, to prepare using traditional manufacturing techniques. It was determined that the filament production and printing process did not degrade the spiropyran units or polymer chains and that the mechanical properties of the specimens prepared with the custom filament were in good agreement with those from commercial PCL filament. In addition to printing photochromic and dual photo- and mechanochromic PCL materials, we also prepare PCL containing a spiropyran unit that is selectively activated by mechanical impetus. Multicomponent specimens containing two different responsive spiropyrans enabled selective activation of different regions within the specimen depending on the stimulus applied to the material. By taking advantage of the unique capabilities of 3D printing, we also demonstrate rapid modification of a prototype force sensor that enables the assessment of peak load by simple visual assessment of mechanochromism.

 

 

For those not familiar with the field of chemistry and the ACS journal, when you see “Supporting Information” in the text click it for another paper’s worth of research result details.

13 Comments on 3D-Printed Mechanochromic Materials

  1. Jason McMullan says:

    So – “We can print materials than change color when they stretch”

    This is incredibly useful! Printed parts with built-in strain gauges!

  2. Jason McMullan says:

    So – “We can print materials than change color when they stretch”

    This is incredibly useful! Printed parts with built-in strain gauges!

  3. Suzi Silva says:

    This is very very neat stuff. Kudos guys!

    • ganter says:

      Thanks, we have more cool stuff coming. As you know not everything in the lab is “open” so it takes a while to get the information out.

  4. Suzi Silva says:

    This is very very neat stuff. Kudos guys!

    • ganter says:

      Thanks, we have more cool stuff coming. As you know not everything in the lab is “open” so it takes a while to get the information out.

  5. Craig P says:

    Any chance of being able to get some of the “color stress” fillament so a makerspace can mess around with it?

  6. rob says:

    Printed parts with built-in strain gauges, neat!

  7. Lesan says:

    How much strain it needs for color change ?

    • AJ Boydston says:

      It really depends on the material. For the thermoplastic PCL, it has to exceed the yield strain before mechanochemistry occurs. Plasticization, etc. can be used to modify the onset. Other papers in the field demonstrate different onset strains for mechanochromic responses. The specimens in our papers yield and change color around 40 – 60% strain, if I recall.

  8. AJ Boydston says:

    We’ll have some of this filament on display at our upcoming symposium (https://artsci.washington.edu/content/3-d-printing-symposium). Also happy to discuss some arrangements for getting this filament out into the community. -AJB

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