Inspirational plants

Wikimedia Commons.

Plants supply us – and other organisms – with many solid resources, e.g. food, medicines, shelter, drinks. Something that is more intangible – but no less important for that – is the inspiration plants provide in the field of biomimetics (biomimicry), ‘the examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems’. The latest example from the plant world concerns hydration-dependent opening of the seed capsules of the ice plant Delosperma nakurense, studied by Matthew Harrington et al. (Nature Communications 2: 337; doi:10.1038/ncomms1336). In language not usually seen in connection with biological phenomena, the team found that ‘this reversible origami-like folding pattern proceeds via a cooperative flexing-and-packing mechanism actuated by a swellable cellulose layer filling specialized plant cells…’, which is ‘…translated into a bidirectional organ movement through simple geometric constraints embedded in the hierarchical architecture of the ice plant valves’. Is it just me who thinks that this style of expression takes away some of the magic and mystery inherent in the natural phenomenon itself? Be that as it may, musing on the relevance of this phenomenon, the group propose that: ‘Extracted principles from this reliable and reversible actuated movement have relevance to the emerging field of “programmable matter” with applications as far-reaching as the design of satellites and artificial muscles’. Ice-plant-inspired artificial muscles? Extra-terrestrial satellites? A scientific paper illustrated with genuine origami figures? Now that really is ‘cool’ (and maybe just a bit magical?)! On a related note, researchers at the University of Michigan and Penn State University (both USA) are exploring the biomimetic potential of the aptly named sensitive plant (Mimosa pudica) – which ‘drops’ its leaflets when touched – to develop a new class of adaptive structures ‘designed to twist, bend, stiffen and even heal themselves’. And – in a 21st Century take on a much older idea – Evan Ulrich and co-workers (Bioinspiration & Biomimetics 5: 045009; doi:10.1088/1748-3182/5/4/045009) have designed remote-controlled robotic versions of ‘samaras’, the helicopter (strictly, monocopter)-like fruits of certain trees such as those of the Acer genus. Ulrich plans to develop the technology for applications in satellite communications and 3-D mapping (http://www.physorg.com/news/2011-01-robotic-tree-helicopter-video.html). For those who want to find out more about plant-inspired engineering solutions, I recommend Felix Paturi’s book Nature, the mother of invention . [And in case you were wondering, origami is NOT the Japanese art of botanicomimetics.]