Researchers over at the Bristol Robotics Laboratory in London may well be on the way to developing the ultimate expression of man-made symbiosis. They've developed an artificial heart powered by a very unusual fuel source: human urine. That's right, in the future, going to the washroom might well mean you're powering a new generation of robots.
They've coined their invention as "EcoBot," and explain that the power core of the machine will be modeled after the human heart. This artificial heart will incorporate materials known as "shape memory alloys," that serve as the muscles; researchers say that the completed model of their artificial heart could be used to deliver a robot's primary source of fuel. This is the fourth generation of "EcoBot" created by the institution in the past ten years. What each of these robots share in common is that they make use of microbial fuel cells - fuel cells which incorporate live micro-organisms - in order to generate power and digest waste matter.
Robots which incorporate such cells could well become automated global custodians simply by existing: the organization has already demonstrated that their machines are capable of generating power from rotten fruit and vegetables, dead flies, waste water, sludge, and now, human urine. Presumably, they're working on making these cells more efficient as time goes by: at the moment, they're hardly capable of providing enough energy to power a working robot.
If memory serves, I believe I've covered these same fuel cells before.
That's not the only problem with the artificial heart, either. Currently, the device uses conventional motor pumps to deliver liquid waste to the fuel cells; these pumps are prone to blockages and mechanical failures. Aside from that, it works similarly to a human heart, compressing a pump to force the waste liquid out towards the cells.
When the 'heart' is heated up by an electric current, the shape memory alloys of which it is comprised compresses down onto a soft region in the heart-pump's center. This causes the waste fluid to be ejected through an outlet and pumped towards the EcoBot's fuel cells, which in turn power the rest of the robot. The muscles then proceed to cool and relax when deprived of an electric
charge, allowing more fluid to be drawn in for another cycle. Currently, this assembly is roughly self-sufficient: a stack of 24 microbial fuel cells generate enough
electricity to charge a capacitor, which in turn provides enough energy to contract the heart for another cycle.
"The artificial heartbeat is mechanically simpler than a conventional electric motor-driven pump by virtue of the fact that it employs artificial muscle fibers to create the pumping action, rather than an electric motor, which is by comparison a more complex mechanical assembly," explained Centre for Fine Print Research's Peter Walters."
So, there you have it. We might be getting a glimpse at what the robots of the future might look like; a race of eco-friendly machines powered on the waste produced by human society. That's just a little a bit more comforting than an impending singularity, no?