Reversible surface instability patterns correspond to external stimuli such as changes in temperature, electric potential, UV, and pH, is of great interest for advanced integrated micro-devices design. In previous work, the elastic creasing instability pattern was successfully programmed on thin hydrogel layers by applying a direct current electric voltage to underlying electrodes. Here, we present an improved system with micro-engineered topographical electrode, expecting to achieve accurate creasing localization, and effective flat-creasing transition. Using topographical electrodes with dimensions approaching the film thickness, a slight decreasing on critical voltages are observed up to ~0.3 V. The self-folding part of crease is more linear thereby the strain transport uniaxially when forming the crease. To understand the creasing mechanics, we experimentally demonstrate an in vivo strain mapping technique with fluorescence microscopy. Specific mark patterns are bleached on the substrate surface and the strain is reflected by tracing the displacement of the bleached mark when electrically triggering the crease. A nonlinear strain transportation is reflected with statistical analysis when the crease forms. This results offer a strong evidence on how surface strain transfers when the crease forms or grows, with experimental time-scales. Further application of this technique can dynamically measure the 3D strain transferring inside the gel substrate.
|Publication status||Published - 12 Mar 2015|
|Event||Fourth International Conference on Multifunctional, Hybrid and Nanomaterials (Hybrid Materials 2015) - Sitges, Spain|
Duration: 12 Mar 2015 → …
|Conference||Fourth International Conference on Multifunctional, Hybrid and Nanomaterials (Hybrid Materials 2015)|
|Period||12/03/15 → …|