Literature

In his book Insectivorous plants, Charles Darwin wrote of Dionaea muscipula: "This plant, commonly called Venus' fly-trap, from the rapidity and force of its movements, is one of the most wonderful in the world" and that it "is one of the most beautifully adapted plants in the vegetable kingdom". The trap closure mechanism is activated by the mechanical stimulation of triggers hairs on the leaf surface, although the details are not understood as well as we would like. Research into post-stimulation mechanical closure has been published in various places by Forterre et al (2005), showing that "snap-buckling instability" is the key. The leaf surface snaps from a concave curvature to a convex with 60% of the displacement occurring in 1/10 second. The researchers write: "by squeezing the leaves with our fingers we were able to induce a snap transition mechanically, indicating that the leaf was indeed in a bistable configuration."
This biological example of a process leading to rapid movement has inspired others to achieve biomimetic goals. Holmes and Crosby report on their research as follows:

"This snap-transition is due to the onset of an elastic, snap-through instability similar to the capture mechanism of the Venus flytrap. The response rates can be over two orders of magnitude faster than the typical response of shape-memory polymers, and the sensitivity and rate of the response can be tuned with predictable geometric and/or material property changes. Based on materials choice, a wide variety of external stimuli can trigger this stress development, such as temperature, pH, solvent swelling, magnetism, electric current, and light. This strategy has great potential for the design of responsive surfaces, which will impact a variety of applications including: release-on-command coatings and adhesives, on-command frictional changes, instant modification of optical properties at an interface, rapid response drug delivery, chemical sensing, and antimicrobial devices."

The concluding comment from Forterre et al was this:

"This ingenious solution to the problem of scaling up movements and speed from the cellular to the organ level in plants, nature's consummate hydraulic engineers, shows how controlling elastic instabilities in geometrically slender objects provides an alternative to the more common muscle-powered movements in animals."

The use of anthropomorphic language by researchers is typical whenever systems that exhibit exquisite design are being studied: this "ingenious solution" and plants as "nature's consummate hydraulic engineers". Our scientific culture precludes any reference to evidence for the handiwork of an intelligent designer. It is always worth remembering that the pioneers of biological research, including John Ray the botanist, had no inhibitions about attributing such evidences of design to a Person rather than an impersonal process.
It should not escape the attention of readers that the Venus Flytrap has all the elements of a mouse trap: the mechanical closure system involving snap-through instability, the activation mechanism resulting from the stimulation of triggers hairs by insects, the requirement for very rapid closure if the device is to be successful at all, and so on. Added to which, this trap opens again automatically, has a built-in digestion system and more. Take away any of these elements, and the mechanism ceases to perform any useful function. One day, this "most wonderful" plant may be written up as an IC system, refuting Darwin's claim that it is a product of adaptation.

Snapping Surfaces
D. P. Holmes, A. J. Crosby
Advanced Materials, November 2007, 19(21), 3589-3593 | DOI: 10.1002/adma.200700584

First paragraph: The responsive mechanism of the Venus flytrap has captured the interest of scientists for centuries. Although a complete understanding of the mechanism controlling the Venus flytrap movement has yet to be determined, a recent publication by Forterre et al.[1] demonstrates the importance of geometry and material properties for this fast, stimuli-responsive movement. Specifically, the movement is attributed to a snap-through elastic instability whose sensitivity is dictated by the length scale, geometry, and materials properties of the features.[2] Here, we use lessons from the Venus flytrap to design surfaces that dynamically modify their topography. We present a simple, robust, biomimetic responsive surface based on an array of microlens shells that snap from one curvature (e.g., concave) to another curvature (e.g., convex) (Fig. 1) when a critical stress develops in the shell structure. This snap-transition is due to the onset of an elastic, snap-through instability similar to the capture to the capture mechanism of the Venus flytrap.

See also:

Forterre Y, Skotheim JM, Dumais J, Mahadevan L., How the Venus flytrap snaps, Nature 2005, 433, 421-425.

Narayan, A.L., Venus flytrap inspires adaptive optics, PhysicsWorld.com, 4 December 2007