From Buckliphobia to Buckliphilia: Embracing the mechanical instabilities of slender structures

Slender structural elements (e.g., rods, plates and shells) under compression are ubiquitously subjected to mechanical instabilities. Across length-scales, buckling has traditionally been regarded as a first route toward failure and is therefore to be avoided; an approach that we refer to as Buckliphobia. By contrast, Buckliphilia is a more recent and burgeoning trend that envisions mechanical instabilities of slender structures as opportunities for scalable, reversible, and robust modes of functionality that are first to be predictively understood in order to then be harvested.

In this talk, I will present a series of representative experimental studies of both Buckliphobia and Buckliphilia, with a focus on problems involving thin elastic rods and shells:  i) lockup through buckling of coiled-tubing in the oil/gas operations; ii) buckling of flagella as a mechanisms for reorientation during bacterial locomotion; iii) modulation of critical buckling loads of thin shells by strategically engineered imperfections; and iv) periodic buckling patterns of shell structures for switchable and tunable aerodynamic drag reduction.

The main common feature underlying these various problems is the prominence of geometry, and its interplay with mechanics, in dictating complex mechanical behavior that is relevant and applicable over a wide range of length scales. The fundamental challenge in these studies lies in rationalizing the geometric nonlinearities that arise in the post-buckling regime. From an engineering perspective, Buckliphilia offers unprecedented opportunities for novel applications.