User research at BESSY II: How water moves glass

A new generation of sensors: The scales of the petrified cone move upward against gravity, and on drying back to their starting positions. </p>
<p>

A new generation of sensors: The scales of the petrified cone move upward against gravity, and on drying back to their starting positions.

© WZS

In the realm of plants, capillary forces are a widely observed impetus for actuation. They are the physical basis for the expansion of porous materials during uptake of fluid. Such materials include the cones of conifers with their readily observable movement during drying or wetting. Scientists at the Chair of Biogenic Polymers of the Technical University Munich, located at the Science Center Straubing, have succeeded in retaining this plant-derived movement when the respective plant has been replaced by an artificial petrification process. Elaborate analyses at the synchrotron source BESSY II in Berlin showed that the internal structure of the pine cone was retained. Thereby, they laid the foundations for a new generation of sensoric materials.

"For the first time we applied a previously developed and refined 'bio-templating' process to create materials with a structure-based functionality- in cooperation with the Institute of Physics of the Austrian Montanuniversitaet Leoben and the Max-Planck-Institute for Colloids and Interfaces in Potsdam", said Dr. Daniel Van Opdenbosch, who is working at the Science Center Straubing. With this approach, one can artificially petrify pine cones, completely transforming the biological components into the technical material silica glass. Elaborate analyses at the synchrtoron source BESSY II in Berlin showed that the internal structure of the pine cone was retained. Crucially, it was petrified completely and accurately – down to the smallest hierarchical level of only millionths of millimeters.

Van Opdenbosch: "We could induce the obtained samples to move in a similar manner as their biological originals during the uptake of moisture. The scales of the petrified cones move upward against gravity, and on drying back to their starting positions."

The scientists hope that the precise templating of plant structures, and the corresponding retention of their characteristic properties, will be a pathway for the development of functional materials. Based on the current results, they say that the preparation of porous ceramic multilayer-sensors is possible with comparatively low expenditure. Such novel sensors react to changes in moisture with angular movement. They could therefore be used to measure, switch or control in chemically or physically aggressive environments. Conventional bimetal or other bilayer actuators are, due to their composition of metals or polymers, prone to corrosion through acid- or base attacks, as well as oxidative, thermal or physical degradation. Against all of these factors, ceramic oxides, such as silica glass, are particularly resistant. 

The project "Hierarchically structured porous ceramics and composites from nanocasting of plant cell walls" was carried out in the frame of the Priority Program 1420 "Biomimetic Materials Research: Functionality by Hierarchical Structuring of Materials" funded by the German Science Community (Deutsche Forschungsgemeinschaft).

More information at the news site of WZS

The scientists published their work in the journal "Advanced Materials" (May 6th 2016, DOI-number 10.1002/adma.201600117).

TU München/WZS

You might also be interested in

  • HZB physicist appointed to Gangneung-Wonju National University, South Korea
    News
    25.01.2023
    HZB physicist appointed to Gangneung-Wonju National University, South Korea
    Since 2016, accelerator physicist Ji-Gwang Hwang has been working at HZB in the department of storage rings and beam physics. He has made important contributions to beam diagnostics in several projects at HZB. He is now returning to his home country, South Korea, having accepted a professorship in physics at Gangneung-Wonju National University.
  • Scientists Develop New Technique to Image Fluctuations in Materials
    Science Highlight
    18.01.2023
    Scientists Develop New Technique to Image Fluctuations in Materials
    A team of scientists, led by researchers from the Max Born Institute in Berlin and Helmholtz-Zentrum Berlin in Germany and from Brookhaven National Laboratory and the Massachusetts Institute of Technology in the United States has developed a revolutionary new method for capturing high-resolution images of fluctuations in materials at the nanoscale using powerful X-ray sources. The technique, which they call Coherent Correlation Imaging (CCI), allows for the creation of sharp, detailed movies without damaging the sample by excessive radiation. By using an algorithm to detect patterns in underexposed images, CCI opens paths to previously inaccessible information. The team demonstrated CCI on samples made of thin magnetic layers, and their results have been published in Nature.
  • Recommended reading: Bunsen magazine with focus on molecular water research
    News
    13.01.2023
    Recommended reading: Bunsen magazine with focus on molecular water research
    Water not only has some well-known anomalies, but is still full of surprises. The first issue 2023 of the Bunsen Magazine is dedicated to molecular water research, from the ocean to processes in electrolysis. The issue presents contributions from researchers cooperating within the framework of a European research initiative in the "Centre for Molecular Water Science" (CMWS). A team at HZB presents results from the synchrotron spectroscopy of water. Modern X-ray sources can be used to study molecular and electronic processes in water in detail.