Military by nature: biomimetic inspiration for future armies

Whenever we humans are stuck for ideas on how to make things better, there’s a guarantee that nature already has it figured out. By looking to nature’s time-tested and sustainable approach to life, we can design and build extraordinary solutions for the engineering and technology world, otherwise known as biomimetics, or biomimicry.

The military is always looking to improve its arsenal and where better to look than Mother Nature, where the best ways to handle problems are organic.

Robotics: Cyborg cockroach

Engineers at the University of Connecticut (UConn) have managed to direct the movement of a cockroach using a tiny electronic backpack. How adorable?

Cockroaches are pretty indestructible – put a bomb on it, get it over enemy lines, activate the device. Everyone dies, the armoured bug probably survives.

The idea of making insects do what you want using electronics is not new – biobots have been on engineers’ brains for over a decade. Yet UConn’s microcircuit is different, giving operators a greater degree of handling insect movement, real-time feedback of the bug’s neuromuscular response to artificial stimuli, and multi-channel avenues for stimulating the nerve tissue.

Future biobots could be used in the military and search and rescue operations. Abhishek Dutta, assistant professor of electrical and computer engineering at UConn, who developed the circuit with researcher Evan Faulkner, says: “We believe our microcircuit provides a more sophisticated and reliable control system that brings us a step closer to real-world implementation of this technology.”

Dutta, who specialises in control system optimisation and cyber-physical systems, used a Madagascar hissing cockroach as the pack mule.

Dutta and Faulkner say the microcircuit inside the backpack allows more reliable and precise control of insect motion. Incorporating a 9-axis inertial measurement unit, it can detect the roach’s six degrees of free motion, its linear and rotational acceleration, and its compass heading.

The backpack also has a sensor for ambient temperature, as roaches are more likely to go walkies when it’s warmer.

Wires from the device are attached to the insect’s antennae lobes. Using a run-of-the-​mill mobile phone, you can control the bug’s movements via a Bluetooth transmitter and receiver. Tiny electrical impulses sent to the roach’s nerve tissue in either antenna lobe make it think it has found an obstacle, so a teeny charge to the left antenna makes the bug move to the right, and vice versa.

This kind of bug tech still has a way to go, but a cockroach with a backpack that could save your life could well be on its way to you.

Biomimicry: Swarm in the sky

The US Defence Advanced Research Projects Agency (Darpa) has been busy working on biomimicry.

Its OFFensive Swarm-Enabled Tactics (OFFSET) programme is aimed at enabling small-unit infantry forces to use swarms of small weaponised drones – 250 robots or more – to complete complex missions. To do this, OFFSET is studying the collective behaviour of swarming found in nature as well as human-swarm teaming (they do this by designing a game to explore, evolve and evaluate swarm tactics).

Fish, birds, insects and even humans naturally form groups. And, like all groups, when the density gets to a certain point, a collective consciousness occurs, rather than individual thought. This can be witnessed when a flock of birds changes direction, for example, or when a school of fish forms a giant ball when under attack.

Darpa has also enlisted developers to create a game environment that experiments with swarm tactics in a virtual realm, awarding Phase 1 contracts to teams led by Raytheon BBN Technologies (Cambridge, Massachusetts) and the Northrop Grumman Corporation (Linthicum, Maryland).They must design a system soldiers can use to control a swarm of drones using interactive technologies such as voice and gesture recognition, and augmented reality (AR) and virtual reality (VR).

Camouflage: Discreet like an octopus

Now you see me, now you don’t. Now you see me. Oh wait, now you don’t.

Like our fine, tentacled marine friends, we may soon be able to precisely match our surroundings in a few seconds, all thanks to the work of Leila Deravi, assistant professor of chemistry and chemical biology at Northeastern University, USA, and her team.

Cephalopods, like the octopus, squid and cuttlefish, have chromatophore organs, which look like hundreds of multi-coloured freckles on the surface of their bodies. These make the skin quickly change colour.

The team isolated the pigment granules in the organs, which come in shades of red, yellow, brown and orange. Their optical qualities were used to make ultra-thin films and fibres rich in colours that could be incorporated into textiles, flexible displays and future colour-changing devices. Deravi’s lab collaborated with the US Army Natick Soldier Research, Development, and Engineering Center (Natick Labs) for the study.

Chromatophores are akin to freckles on human skin that appear over time, and the researchers say cephalopods’ freckles open and close within a fraction of a second to give rise to a continuously reconfiguring skin colour. Underneath the chromatophores is a layer of iridophores, which act as a mirror, reflecting all colours of visible light.

Removing individual pigment particles from the squid uncovered their abilities as static materials. One particle is 500 nanometres in size – 150 times smaller than the diameter of a human hair. Deravi’s team layered and reorganised the particles and found they could produce an expansive colour palette.

“From a scientific and technical engineering perspective, understanding how light scattering affects colour is very important, and this is an exciting new development in the field of optics in biology,” says Richard Osgood, from Natick Labs. “This is an unusual harnessing of optics and physics knowledge in scattering to understand biological systems.”

Protection: Friends with insect benefits

Can you imagine having insects as your friends? Quite sweet, right? However, scientists are getting pretty worried about it.

Darpa’s Insect Allies programme is setting out to get bugs to transfer viruses from plant to plant. Not bad viruses, though.

Plant-eating insects transmit most plant viruses. Darpa wants to exploit this by engineering genes with protective traits into the viruses, which the insects carry, eat their target plants, and give them a defensive boost against threats to the food supply.

Darpa hopes this will provide a great alternative to pesticides, selective breeding, slash-and-burn clearing and quarantine, which often don’t work against emerging threats. These can be pathogens, drought, flooding and dangers “introduced by state or non-state actors”.

However, European researchers have argued that, if successful, these insect allies could be turned sinister by “malicious actors” and spread disease, killing off crop species and harvests.

Hydration: Make your own water

The tiny Namib Desert beetle lives in a region that only gets 2-200mm of rainfall a year. You would think this wee insect would shrivel up like a raisin and die. However, it knows how to keep itself hydrated, by condensing fog on its ridged back, turning it into drinkable droplets, and storing it away.

It’s already inspired a self-filling water bottle back in 2012. Start-up NBD Nano looked into covering a bottle’s surface with hydrophilic (water-attracting) and hydrophobic (water-​repellent) materials. The idea was to get surrounding air to pass over the bottle surface, condense the water vapour, and store it inside.

Researchers from the Massachusetts Institute of Technology have also made a material out of glass and plastic that is bumpy like the Namib beetle’s back. They claim the material could collect liquids, build cooling devices, or be used in a ‘lab on a chip’. The US military even reckon the biomimetic material could help clean up toxic spills.

Sensors: The spy who planted me

Have you ever thought you could turn plants into sensors? Well, Darpa certainly did.

The military always needs accurate and timely information, so the US Department of Defense invests heavily in powerful electronic and mechanical sensor development, and the workforce needed to maintain it.

Traditional sensors are not always up to the task, as the national security landscape is ever-changing and has become far more complex. There are trickier things to detect nowadays.

Darpa’s Advanced Plant Technologies (APT) programme is making simple plants become the next generation of intelligence gatherers. APT researchers will try to engineer heavy-duty, plant-based sensors that are self-sustaining and can be remotely monitored using existing hardware.

The plan is to harness plants’ natural mechanisms for sensing and responding to environmental stimuli, and extend them to detect certain chemicals, pathogens, radiation, and even electromagnetic signals.

By modifying genomes of plants, the hope is to get them to specifically sense and then trigger discreet response mechanisms when a relevant stimulus is present, without damaging the plant. If successful, it will be a stealthy sensing platform that is energy-independent, robust and easily distributed.

Darpa says this could open up new intelligence streams, and “reduce personnel risks associated with traditional sensors”.