In this talk we discuss some new principles of design of hybrid materials – a special group of composite materials in which the geometry of the constituents, viz. their shape and mutual arrangement, plays the role of an additional design parameter. The concept is based on the topological interlocking of the individual elements of the composite providing its structural integrity [1]. Interlocking ensembles of blocks having the shape of one of the five platonic solids, or blocks with concavo-convex surfaces (osteomorphic blocks) will be shown to possess controllable bending stiffness, high energy and sound absorption and a great tolerance to local failures. Of special interest is the possibility of employing active elements, which can be activated through external stimuli. This opens up the possibility of controlled variation of properties of the composites. Some of the test data illustrating this material design concept will be presented. Examples of topological interlocking-based composites as well as 3D-printed structures with embedded ‘micromachines’ that act as actuators [2] will also be shown.
[1] Y. Estrin, A.V. Dyskin and E. Pasternak, Topological interlocking as a materials design concept, Materials Science & Engineering C, 31:1189–1194 (2010).
[2] E. Bafekrpour, A. Molotnikov, J.C. Weaver, Y. Brechet, Y. Estrin, “Responsive materials: A novel design for enhanced machine-augmented composites”, Scientific Reports 4, Article Number: 3783 (2014).