How to Power the Coming Micro-Robot Explorers of the Solar System
Micro-robot explorers will be cheaper and easier to mass produce and deliver to the various planetary bodies of the solar system -- all the way to Pluto and beyond.
It is not yet clear how to best power these tiny robots -- so far from Earth and the sun. But one idea is to use microbial fuel cells. That approach would work best, of course, if the microbes were able to find a native source of food on the planetary body. More:
Microrobotic explorers, powered by microbial fuel cells, could represent an efficient and reliable energy source on a planet without human intervention.Microbial Fuel Cell.org
Microbial fuel cells harness the metabolic processes of bacteria, sending harvested electrons through an anode-cathode-resistor circuit to generate electricity. The advantages are that bacteria can be squashed into a battery with high energy density compared to traditional lithium-ion power sources, and the ability of microorganisms to reproduce acts like a natural battery charger.
Scott reckons that a portion of the microbial energy would be used to maintain onboard electronics and control systems, while the rest would be directed toward slowly charging a battery or capacitor. Once enough energy is stored, the autonomous robot would be able to use a more power intensive scientific instrument or to propel itself forward.
His research will focus on a pure culture anaerobic bacterium, such as Geobacter sulfurreducens, and look at ways to increase the energy produced by MFCs, and eliminate the existing bulk associated with the battery infrastructure, such as large, power intensive pump systems.
"As we move forward in the utilisation of MFCs as an energy generation method, this research begins to lay the groundwork for low powered electronics with a long-term potential for space and robotic applications," says Scott. Microbial fuel cells coupled with extremely low-power electronics and a low energy requirement for mobility addresses gaps in power technology applicable to all robotic systems, especially planetary robotics." _Wired.co.uk
Wikipedia: Microbial Fuel Cell
The Wired.co.uk article above did not explain specifically where the bacteria were to get their food. If bacterial fuel cells are eventually used to power micro-robotic space explorers, they will need to be fashioned specifically for the type of food resource available on the targeted space body.
Of course, what we actually want to send to the planetary bodies of the solar system are micro- and nano-robotic systems that are able to self-power, self-reproduce, and work together as swarm intelligences. They should function not only as exploratory probes, but as preparatory builders of infrastructure -- preparing habitats and resources for later human occupants.
It is not clear whether bacterial fuel cells can provide enough power for that more difficult secondary mission. But they should be kept in mind as one power source among many possibilities, including nuclear power packs and charging stations.
Labels: fuel cells