INNOVATIVE MATERIALS
Illustration based on picture from Nature Communications
Complex glass geometric structures
Origami glass Glass is a great material in many ways, but the detailed design of glass products is not easy. This has to do with the brittle properties of the material and the high temperatures at which the (conventional) molding processes work. In recent years, research into the use of silica-polymer composites as a prepolymer for glass production has shown that this technique offers perspectives for making complex geometric shape structures of glass, but this technique still has drawbacks. The same goes for 3D printing glass. Researchers from China’s Zhejiang University have now developed a method that makes it possible to create three-dimensional transparent glass using origami techniques. The question is: ‘how to fold glass?’
Glass is indispensable in many applications, from tableware to architectural constructions and telephones to works of art. In fact, glass is indispensable in many applications because of typical properties such as optical transparency, wear resistance and thermal and chemical stability. Still, processing glass remains difficult, especially when it comes to complex geometries. Processing options are often limited compared to metal and polymers. This is due to the brittle nature of the material and the need that is often present to achieve full transparency.
3D printing
Conventional glass shaping processes operate under challenging conditions such as high temperature or chemical etching. Although sol-gel techniques make it possible to produce glass shapes under milder conditions, the geometric complexity is limited by the casting technique. Another solution could be to use silicapolymer composites as a precursor for glass making, which opens the way to low temperature casting. The material can then be machined and sintered into the final 3D glass shape. Finally - without the use of casting - such precursor composites (prepolymers)
glass also can be be shaped with a 3D printer. Universities and research institutes all over the world are looking for new processes when it comes to 3D printing of glass and although interesting results have been achieved, apparently no breakthrough has been forced yet (see box on following pages).
Origami
Researchers at Zhejiang University in Hangzhou, China, have now come up with something different. They developed a method that makes it possible to make three-dimensional transparent glass using origami techniques.
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