News Technology 14 February 2017
3 minute read 

How to find and destroy landmines – safely


Sniffer bees, genetically modified weeds and metal-detecting drones might help unearth and blow up hidden, deadly bombs.


A sniffer rat trained to find landmines in Mozambique.
Xavier ROSSI / Gamma-Rapho / Getty Images

Hidden and lethal, landmines are a lingering legacy of war, rendering huge swathes of territory impassable. Exactly how many landmines lie undiscovered around the world is unknown, but estimates run into the tens of millions.

Some countries are loaded with them. Cambodia – with an area of just 180,000 square kilometres – is thought to contain between four and six million. Their presence hinders urban expansion and agriculture. Around the world, they kill between 15,000 and 20,000 people every year – more than a third of them children.

Finding and disabling landmines presents unique challenges. In 2015, according to the United Nations’ annual Landmine Monitor report, mine clearance efforts destroyed nearly 158,000 antipersonnel mines and 14,000 antivehicle mines.

Military forces can use large vehicles to clear out minefields in former combat zones, but different tactics are needed to deal with the problem in civilian areas.

Let’s take a look at a few current demining techniques – and ideas under development.

A military engineer of the Russian Armed Forces International Mine Action Centre clearing eastern Aleppo of mines in December 2016.
TASS / Getty Images

Metal detectors

These use a magnetic field to identify the steel, copper, aluminium or lead components of buried mines. Unfortunately, they are indiscriminate machines and will react equally to a firing pin, a pressure plate, a piece of discarded shrapnel or an old soft drink can. For this reason, their use is highly labour-intensive, with some estimates of hit rates as low as one in 1,000.

These bees were part of an experiment to determine their ability to locate mines.
Joe Raedle / Getty Images

Animals

Why not harness nature’s power to do the job? Dogs and rats can be trained to sniff out some types of explosive chemicals. Using live detectors is both faster and more reliable than using handheld devices, and, being small, rodents and dogs are less likely than humans to set a mine off should they tread on one.

Dogs can become disorientated by competing scents in areas with a lot of buried bombs, making rats better candidates in some situations. A company in Montana in the US is training honeybees to do the job.

Demonstration of a subsurface radar imaging device known as RASCAN.
BEN STANSALL / AFP / Getty Images

Ground-penetrating radar

High-frequency radar waves sent into the earth, reflected and detected can tell an operator about the size and shape of buried objects. But rocks and water pockets create frequent false positives, and some types of soil, such as clay or shale, reduce the system’s penetrative power to under a metre.

A prototype of six-wheeled robot 'HUMI' ('Humanitarian Demining').
DIETER NAGL / AFP / Getty Images

Robots

The obvious answer isn’t viable yet – and doesn’t look to be anytime soon. While current robots can be equipped with the same detectors that humans use, they generally aren’t able to move easily over uneven ground, rendering them unsuitable in most areas.

Thale cress (Arabidopsis thaliana).
MAURO FERMARIELLO / SCIENCE PHOTO LIBRARY

Plants and bacteria

Some species of plants and bacteria have been genetically modified to react to the presence of explosive chemicals. Thale cress (Arabidopsis thaliana), for instance, can be bred to turn from green to red in the presence of nitrous oxide, a chemical that leaks from some types of unexploded bombs.

In 2016, researchers at the Massachusetts Institute of Technology in the US announced that they had successfully engineered spinach not only to detect trace elements exuded by explosives but also – via implanted nanotubes – to communicate the fact to a handheld receiver.

Dutch brothers of Afghan origin Massoud and Mahmud Hassani push the 'Mine Kafon', a wind-driven gadget to clear anti-personnel mines, at their Eindhoven workshop in 2012.
Jan Hennop / AFP / Getty Images

Mine Kafon

Beginning its life as an art project, the Mine Kafon has morphed into a wind-powered, disposable mine destruction device – funded by Kickstarter.

Designed by Massoud Hassani, who grew up in Afghanistan before finding safe haven in The Netherlands, the Kafon has been described as “a giant clump of dandelion seeds”. Essentially an autonomous, GPS-equipped sphere, the device roles across minefields, detonating any mines it encounters. Each device can blow up three to four devices before being too badly damaged to continue.

Afghan refugee Massoud Hassani flying an anti-landmine drone called a 'Mine Kafon drone' in Eindhoven.
Jan Hennop / AFP / Getty Images

Hassani and colleagues are currently also developing a drone-equipped variation. It hovers around four centimetres above the surface, detects mines with a robotic metal detecting arm, then places a small detonator with a timer on each mine it finds.

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Contrib vishnuvarma.jpg?ixlib=rails 2.1
Vishnu Varma R Vejayan is a physics student from Queen Mary University of London with an interest in scientific writing and research in physics. He interned at Cosmos in early 2017.