Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD 20723, USA.
Department of Chemistry, Duke University, Durham, NC 27708, USA.
Molecules. 2019 Feb 1;24(3):542. doi: 10.3390/molecules24030542.
Several technologies can be used for measuring strains of soft materials under high rate impact conditions. These technologies include high speed tensile test, split Hopkinson pressure bar test, digital image correlation and high speed X-ray imaging. However, none of these existing technologies can produce a continuous 3D spatial strain distribution in the test specimen. Here we report a novel passive strain sensor based on poly(dimethyl siloxane) (PDMS) elastomer with covalently incorporated spiropyran (SP) mechanophore to measure impact induced strains. We have shown that the incorporation of SP into PDMS at 0.25 wt% level can adequately measure impact strains via color change under a high strain rate of 1500 s within a fraction of a millisecond. Further, the color change is fully reversible and thus can be used repeatedly. This technology has a high potential to be used for quantifying brain strain for traumatic brain injury applications.
几种技术可用于测量高速冲击条件下软材料的应变。这些技术包括高速拉伸试验、分离式 Hopkinson 压杆试验、数字图像相关和高速 X 射线成像。然而，这些现有技术都无法在试样中产生连续的三维空间应变分布。在这里，我们报告了一种基于聚二甲基硅氧烷 (PDMS) 弹性体的新型被动应变传感器，该传感器通过共价键合的螺吡喃 (SP) 机械基元来测量冲击引起的应变。我们已经证明，在 0.25wt%的水平下将 SP 掺入 PDMS 中，可以在千分之几秒的时间内通过高应变率 1500s 内的颜色变化充分测量冲击应变。此外，颜色变化是完全可逆的，因此可以重复使用。这项技术在定量评估创伤性脑损伤应用中的脑应变方面具有很高的应用潜力。
