A miniature medicine factory, but potentially also of many other chemical compounds, in the form of a leaf, created at minimal cost and powered by sunlight, seems too good to be true. Nevertheless, researchers from the Eindhoven University of Technology, in the Netherlands, who had earlier worked with a similar but more limited prototype, have managed to create a mini bioreactor, as it is known in technical terms.

As reported in the Green Chemistry journal, one of the advantages of this new device is its ability to work even in very different light conditions by moderating its functions, like a real leaf does, in accordance with light intensity. If the light is too strong, for example, undesirable molecules may form, while under low light conditions the predicted reaction might fall short of expectations.

The ability to adapt itself to different light conditions is assured by three factors. One is a sensor that is able to gauge the light intensity which reaches the internal channels where the reaction occurs, or rather the veins of the leaf, and which produces a signal. Another is a controller which transmits this signal to a micro-pump, and the third factor is the pump itself, which drives the liquids needed for a reaction to the interior of the channels, in order that neither too much nor too little liquid is delivered. All this is enabled by materials that are called luminescent solar concentrators, which act in a similar way to certain molecules present in plants. According to researchers, this mini-factory could provide for important developments, considering its efficiency, independence from fossil fuel energy sources, ease in use and, not least, its low cost, since this system of light adaptation does not cost more than 50 euros.