Science - November 2, 2010

The future: being fed by a microchip

The food of the future will come out of a microchip. Literally. Franciso Rossier-Miranda developed such a chip and is due to get his doctorate for it on Friday.

The technique in which Rossier-Miranda has specialized is called microencapsulation. This means enclosing valuable materials in small capsules for targeted release. In this case, the release of nutrients into the small intestine. Flavours, for example, or probiotics, nutritional supplements or anti-oxidants. The sky's the limit, says Rossier-Miranda. As long as it can be packaged in pills that can be measured in micrometers. Invisible to the naked eye and imperceptible to the tongue.

Microcapsules are not new in themselves, but what Rossier-Miranda does with them is. He builds up the outer shell of the capsules, their packaging, out of layer upon layer of easily available nutrients, in this case pectin and whey proteins. The long fibres (fibrils) of the whey protein ensure strength, a bit like the iron in reinforced concrete. A drop of oil serves as a mould, and also itself contains a valuable substance that needs to be delivered to the right place. Nature builds up shells in this way through a process called adsorption. Rossier-Miranda also makes use of electrostatic attraction as the driving force that builds up the capsule, charging the nutrients and the drop by turns.

The method works but it is slow. 'Building up a shell step by step takes fifteen hours in the lab', explains the doctoral researcher. That is why he developed a chip that carries out the process continuously, efficiently and fast. The chip looks like a glass slide, and it conceals a pattern of barely visible small canals. The oil droplets travel down the main canal, and the nutrients for the shell are transported along the tributaries, with a layer of the shell being formed at every junction. By linking hundreds of these chips, it is quite easy to upscale the process.

The chip is not perfect yet though, says Rossier-Miranda, to put things in perspective. The tiny canals get blocked quite quickly, for example. In a follow-up study, Rossier-Miranda plans to cover their walls with special 'brushes', using a technique borrowed from his Wageningen colleagues in organic chemistry.
It's just a question of time before the first meal is eaten from a micro chip.