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By Oluwaogbon Akinnola

Photo credit: Pixabay

If you’ve read my previous article on Artificial Intelligence, you’ll already know about my fear of the day computers replace us at the top of the food chain. An irrational fear some may say, given the numerous awkward situations autocorrect lands people in. Yet when you consider that Stephen Hawking voiced similar concerns in December last year, you may want to consider being equally vigilant for technological advancements that could bring that day closer [1]. Advancements like ‘Self-Fueled Biomimetic Liquid Metal Mollusk’, a drop of liquid metal that moves like it’s alive..

The Biomimetic Mollusk

The Mollusk is essentially a metal alloy liquid that can move and morph its shape. Whilst nowhere near as sophisticated, you would not be mistaken in imaging the T-1000 from Terminator 2. The surprisingly simple device was created Tsinghua University in Beijing, China as part of materials research. The alloy, known as galistan, is made up of 68.5% gallium, 10% tin, and 21.5% indium which gives it a melting point of 19C so it’s liquid at room temperature [2]. When a drop is put in a sodium hydroxide solution or brine and is ‘fed’ a flake of aluminium for fuel, it can move unaided for around an hour. The drop can move in a straight line or through a guided path and it will morph its shape to fit though complex structures. Alex Mack would be proud.

How Does It Work

The drop has two mechanisms that operate simultaneously to create move it. Firstly a charge imbalance exists across the drop which creates a pressure difference between the front and back of the drop which propels the drop forward. Secondly the aluminium reacts with the sodium hydroxide producing hydrogen bubbles that add to the forward motion making the drop capable of moving at speeds in the order of centimetres per second [3]. This doesn’t sound like much but considering the drop is in the order of millimetres in size, it’s quite the Speedy Gonzales

Not A One-Trick Pony

Yet that’s not all this alloy is capable of. When the drop is kept stationary it transforms from a mini-rover into the world’s first self-powered pump capable of moving 50ml of water a second. Not an incredible amount but the implications are; the device could be developed into a self-powered pump to drive water through a cooling device without the need for an external power source. It is also capable of forming complex shapes and spreading out when an electric current is applied to the drop yet returns to its drop shape when the current is removed, as discovered by both the Tsinghua group and a team at North Carolina State University [4].


Similar self-propelled motors have been created before. However, the Mollusk is the first motor to exist on a macroscopic scale and its potential is on an equally significant scale. A self-propelling motor that can deform to fit the environment opens up doors in all sorts of transportation, especially drug delivery in through blood vessels. The drop’s response to an electrical current could allow for a swarm of independent drops to be controlled, further expanding on substantial potential of the Mollusk. This discovery is part of work looking to develop intelligent robots that can spontaneously change shape, much like a certain robot assassin from future. The Mollusk’s unique qualities provide the potential to open doors in numerous fields, from medicine to utilities, I just hope Skynet is behind one of them.

Check the New Scientist link for a video of the Mollusk.


  1. Cellan-Jones, R. (2014). Hawking: AI could end human race. [online] BBC News. Available at: [Accessed 19 Mar. 2015].
  2. Starr, M. (2015). Terminator draws closer with shape-shifting liquid metal motor. [online] CNET. Available at: [Accessed 19 Mar. 2015].
  3. Zhang, J., Yao, Y., Sheng, L. and Liu, J. (2015). Self-Fueled Biomimetic Liquid Metal Mollusk. Adv. Mater., p.n/a-n/a.
  4. Slezak, M. (2015). Liquid metal brings shape-shifting robot a step closer. [online] Available at: [Accessed 19 Mar. 2015].

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