Some day, when bionic men and women are real, it will be through the cautious but steady advance of body implants such as the new Active Book. This doesn’t sound like what it is, a tiny electronic complex about the size of the nail on the little finger that is implanted in the spinal column of people suffering from paralysis. The researchers, a team from the Engineering and Physical Sciences Council (UK) and led by Professor Andreas Demosthenous, University College London, dubbed their device Active Book because it uses laser technology to cut tiny electrodes from leaves of platinum foil. The foil is folded into a three-dimensional shape, which looks something like a book. Each ‘page’ is used to enclose a nerve root. That’s the particular advantage of the device; it can control several nerve/muscle groups simultaneously.
It’s the packaging of the Active Book that advances the technology. ‘Micro-packaging,’ as it is called is demanding in both design and production. Here the innovation is to include both the electrodes and controller for muscle stimulation in one unit. The unit needed to be small enough so that several of them could be placed into the spinal canal. The heart of the device is a silicon microchip hermetically sealed to prevent water (body fluid) corrosion.
What about power supply? Ah, there’s the rub. The device still requires an external cable for power and monitoring. Even so, this is advancement over previous systems that attach electrodes to the outside of the leg or arm and connect by cable to an external stimulator.
“The work has the potential to stimulate more muscle groups than is currently possible with existing technology because a number of these devices can be implanted into the spinal canal”, said Professor Andreas Demosthenous. “Stimulation of more muscle groups means users can perform enough movement to carry out controlled exercise such as cycling or rowing.”
Pilot studies for the Active Book should begin next year. This means, generally, animal studies first, then three phases (at least) of human trials. This means that even if all trials are successful, the Active Book is several years from approval for widespread use. That’s why bionic people, constructed from thousands of implanted devices, are very much science fiction for at least a decade or two, or three.