Tensegrity and its role in guiding engineering sciences in the development of bio-inspired materials.

Abstract

Tensegrity is the word coined by Buckminster Fuller as a contraction of tensional integrity. A tensegrity system is established when a set of discontinuous compressive components interacts with a set of continuous tensile components to define a stable volume in space. Tensegrity structures are mechanically stable not because of the strength of individual members but because of the way the entire structure distributes and balances mechanical loads. Tensile forces naturally transmit themselves over the shortest distance between two points, so the members of a tensegrity system are precisely positioned to best withstand stress. Thus, tensegrity systems offer a maximum amount of strength for a given amount of material. Man-made structures have traditionally been designed to avoid developing large tensile stresses. In contrast, nature always uses a balance of tension and compression. Tensegrity principles apply at essentially every size-scale in the human body. Macroscopically, the bones that constitute our skeleton are pulled up against the force of gravity and stabilized in a vertical form by the pull of tensile muscles, tendons and ligaments. Microscopically, a tensegrity structure has been proposed for the skeleton of cells. This report contains the results of a feasibility study and literature survey to explore the potential of applying tensegrity principles in designing materials with desired functionalities. The goal is to assess if further study of the principles of tensegrity may be exploited as an avenue for producing new materials that have intrinsic capabilities for adapting to changing loads (self-healing), as with the ongoing reconstruction of living bone under loading. This study contains a collection of literature that has been categorized into the areas of structures, mathematics, mechanics, and, biology. The topics addressed in each area are discussed. Ultimately, we conclude that because tensegrity is fundamentally a description of structure, it may prove useful for describing existing materials, but does not provide guidance in the development of new materials because it does not address the issue of how such structures form.