Scientists at Princeton -who must have never seen The Matrix- have developed a system to convert basic human organ function into electric energy.
The Matrix is a a science fiction action film written and directed by Larry and Andy Wachowski and starring Keanu Reeves and Laurence Fishburne. It depicts a dystopian future in which reality as perceived by most humans is actually a simulated reality while their body heat and electrical activity are used as an energy source.
The kind of technology found in the Matrix to turn humans into batteries is now being developed by Scientist Michael C. McAlpine and his colleagues at Princeton University. McAlpine has developed a promising approach for converting body movements into electricity: printing piezoelectric crystals onto flexible, biocompatible rubberlike material. That energy could be put to work, charging a cellphone, say, or a medical sensor in the body. The problem is how to harvest it.
The act of breathing-of moving the ribs to draw air into the lungs and expel it-can generate about a watt of power,” according to an article by Henry Fountain in today’s NYT Science Times. “And if the potato actually gets up off the couch and walks briskly across the room, each heel strike can produce even more power, about 70 watts’ worth. That energy could be put to work, charging a cellphone, say, or a medical sensor in the body. “It may not seem like it, but even the laziest of couch potatoes is a human dynamo.
Piezoelectric crystals produce an electric current when bent and have many uses — the igniter on a gas barbecue grill being one of them. But highly efficient crystals of the kind that might be useful in the body are made at high temperatures that would destroy most plastics or rubbers. The solution developed by Dr. McAlpine and colleagues, which is described in the journal Nano Letters, is to first make the crystals, in a series of narrow ribbons, on a rigid substrate of magnesium oxide. Then, after the substrate is etched away from the crystals, they are transfer-printed on a flexible biocompatible polymer, called PDMS.
Dr. McAlpine said his team had started building prototypes, in which tiny wires are deposited on the crystals so that the electricity can be harvested. The crystals are also covered with another layer of PDMS to protect them, and to safeguard the body since the crystals contain lead. A first application might be in shoes, to produce enough power to keep a music player or phone charged. But the eventual goal would be to make a flexible power generator that could be implanted in the chest or elsewhere.