The US Navy is investigating the idea of small robots powered by bacteria that could one day explore other planets.
Scientists at the US Naval Research Laboratory (NRL) plan to use advanced microbial fuel cells (MFCs), which generate electricity from the chemical processes of live bacteria, as a long-lasting energy source for an autonomous low-power microrover.
‘The goal is to demonstrate a more efficient and reliable energy source for use in powering small robotic vehicles in environments where the option for human intervention is non-existent,’ said Dr Gregory Scott at NRL’s Spacecraft Engineering Department.
‘Microbial fuel cells coupled with extremely low-power electronics and a low-energy requirement for mobility address gaps in power technology applicable to all robotic systems, especially planetary robotics,’ he added.
MFCs provide long-term durability because the micro-organisms in the fuel cell can reproduce and the bacteria have a high energy density compared with traditional lithium-ion power sources. However, there are still several limitations associated with MFCs — such as their size, weight and power requirements — that the research team is hoping to eliminate.
A portion of the energy generated by the MFC will be used to maintain on-board electronics and control systems, with the remaining energy directed towards slowly charging a battery or capacitor.
When the system has gathered sufficient power from the MFC, it can be discharged to activate a more power-intensive scientific instrument or to propel the rover forward using a novel tumbling or hopping locomotion system.
‘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,’ said Scott.