Nature has always been a source of inspiration for the human being, but never had it been as it happens today for the so-called living materials, living materials: hybrid compounds, which combine the best characteristics of special living organisms with a stable matrix of inorganic particles. This is the concept behind a new “fabric” presented on the pages of Advanced Functional Materials by an international group of researchers coordinated by Anne Meyer, synthetic biologist at Rochester University, NEW.
“Ours – explains Meyer – is the first example of engineered material robust enough for use in the real world and at the same time capable of photosynthesis”. To create it, the team used a bacterial cellulose matrix, which unlike the vegetable one, has particular mechanical properties: flexibility, resistance and above all a remarkable ability to return to its original shape once squeezed. Meyer and colleagues, just like on a sheet of paper, “printed” three-dimensionally a bio-ink based on Chlamydomonas reinhardtii, a special autotrophic microalgae, that is capable of manufacturing nutrients starting from inorganic molecules; in nature it is also known as “green yeast”. Result: a photosynthetic material that combines the self-sufficiency of the alga with the robustness of cellulose.
“A small piece of bio-tissue can be grown on site, to derive more from it,” continues Meyer. In other words, its vegetal nature, and to all intents and purposes “living”, would allow the prototype to self-regenerate, a perfect feature for a great variety of applications: “from artificial leaves resistant to atmospheric agents, to organic skin and clothing”, we read in the publication.
Why should we need it, one may ask. The answer is simple: the great challenge of this century will be to reduce (and absorb) over 1,500 billion tons of excess carbon dioxide that humanity has released into the atmosphere in just over 300 years; the point is that we still don’t know how we will do it. One hypothesis – at the moment little more than embryonic – is precisely that of using materials such as those conceived in Rochester to create artificial leaves that fully simulate the photosynthetic mechanisms of natural ones.
“We worked on the ‘best part’ of the plant, that is the leaf – underlines Meyer – which creates energy in a sustainable way without the need for resources to grow other unproductive parts (the stem and roots ed) “. The bio-material, in fact, is able to convert water and CO2 in oxygen and energy using sunlight: an interesting property, especially for those areas where plants would not grow, if not with great energy and economic expenditure. An example? “Above all, the space colonies,” Meyer replies.
Another possible application is that of skin grafts: “The locally produced oxygen could contribute to wound healing, or trigger healing through phototherapy (a treatment that uses light stimuli ed)”.
But the most promising field, according to the authors of the work, would be precisely that of fashion. A sustainable, economical and above all completely biodegradable bio-clothing could revolutionize a sector that is currently responsible for 10% of global greenhouse gas emissions. With a hypothetical photosynthetic t-shirt, the researchers write in their conclusions, in the future “we will also be able to save water”, since, thanks to its self-regeneration capabilities, it should not be washed as often as conventional ones. “There is still a lot of research to be done – concludes Meyer – but the idea is exciting: imagine a dress that can multiply and be shared with others, almost like a mother yeast”.
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