They Didn't Used to Be a One Trick Pony

Defense Tech notes DARPA has evolved an unconventional attitude about what will make the United States military independent of petroleum.

Robots and plasma weapons, of course. And broadcast energy. Of course.

"...universal connectivity will allow commanders to track individual soldiers and robots as well as logistics system status and readiness,” the summary [of a February Darpa energy workshop] states. These capabilities, coupled with advanced modeling and simulation tools, will allow commanders to rapidly explore and exploit warfighting options, which in the end translates into shorter execution time lines and reduced energy requirements."

Darpa-ites also saw drones as a potential boost to oil alternatives.

"Using more unmanned systems will save energy because they will be smaller and lighter than manned systems that require armor, the summary states. Plus, robots and other unmanned systems “will allow reduction of the number of combat soldiers needed to accomplish the mission, further contributing to reduced energy requirements.”

Electricity will one day be the big replacement for oil, the Darpa conferees believe. And "since electricity can be generated from a variety of sources, it may be possible in 30 years to avoid having to rely on energy and fuel imported into a battlespace," Inside Defense notes.

The military would also need portable generators and "'ultra-high-capacity' electric storage devices to support directed-energy weapons and other 'futuristic gun systems' that require massive amounts of energy in short bursts."

But those ray guns shouldn't be wired up to the generators. The energy should be beamed through the air, instead. "This technology will be valuable because power lines are highly vulnerable to sabotage," the Darpa summary observes. Of course they are.

Yes, indeed, we are running out of fossil fuels, so the solution?

Better robots and ray guns, of course.

Of course, this is now. Prior to 2001 (you know- back when DARPA and Al Gore were busy inventing the internet), DARPA had a rather more forward view of alternative energy called Energy Harvesting:

Objective

The objective of this program was to develop energy storage and conversion components capable of harvesting energy from ambient sources (e.g., solar, wind, thermal, wave-action, currents [streams, rivers, deep ocean], chemical and thermal gradients, barometric fluctuations, biological, electromagnetic radiation, and human activities), and integrate those components with power delivery systems to increase the endurance by a factor of 10 over conventional systems.

Impact

Technologies that can harvest energy from environmental sources can significantly reduce or eliminate battery requirements. For low-power levels, place and forget sensors are feasible, as they will operate indefinitely. This will eliminate the need for battery replacement in highly dangerous or sensitive areas.
For the soldier, energy harvesting technology can be integrated with electronic components, reducing pack weight and increasing the total energy available, and therefore mission endurance.

Program Approach

Major thrusts include mechanical to electrical conversion via ocean currents, wave, heel strike and pack motion by using piezoelectric and electrostrictive materials; thermal to electric conversion at ground-air and ocean-air interfaces by using thermoelectric materials; harvesting energy from chemical gradients in ocean sediments; and exploring naturally occurring fuels (e.g., cellulose and sugars) as a source of hydrogen for small fuel cells. As the energy content is low for these processes, it is critical to integrate harvesting technology with the total power system and match the duty cycle of the application so that losses are minimized.

Major Accomplishments

The following major accomplishments have been achieved for this program, which spanned from FY97 to FY01:

* Achieved the highest specific energy density for a field-activated electroactive polymer and incorporated it into a boot that harvests 300 mW from walking (previous heel strike technology was 1 mW). One watt or greater per boot is achievable using this technology.

* Established the proof of principal for a new generation of nuclear batteries using icosahedral borides.

* Developed an implantable biofuel cell that operates on blood glucose and oxygen.

* Developed and deployed a benthic fuel cell that harvests energy from marine sediments.

* Established the basis for ATP-fueled biomolecular motor devices by integrating individual biomolecular motors with nanostructures and evaluating their mechanical properties.

That was then. So what happened to all these great ideas?

Darth Rumsfeld.