Metabots, Legless Jumping Robots and Engineered Metamaterials
May 8
This week we examine a new material that can expand, assume new shapes, move and follow commands without a motor or gears. Sounds very much like the T-1000 from Terminator 2 to me. We have little time to prepare. We investigate a new legless jumping robot that jump to the height of a basketball hoop. We discover a new metamaterial that is both ultra strong and stretchy. Finally we look into a new air driven propulsion system for local ferries. No more noisy and polluting diesel engines.
Metabot
I am sure that most of us have seen Terminator 2 where the T-1000 made its debut. The T-1000 was a self reforming robot terminator sent back from the future to kill the future rebel leader (John Connor) as a child. The robot looked fanciful when the movie was released in 1991 however only 34 years later a team at Princeton University have developed a material that performs in a similar way to the T-1000.
This new material can expand, assume new shapes, move and follow commands even though it has no motor or internal gears. The material can be transferred from material to robot and back again. The material is controlled via an external magnetic field.
The new metamaterial was inspired by the folding art of origami. The material was engineered to depend upon the material’s physical structure rather than its chemical composition. Built from custom made magnetic composites the material can change its structure, causing it to expand, move and deform in different directions. All of this change is remote, no need to touch the metamaterial.
In addition to a new breed of assassination robots there are a range of envisaged uses for the material. The team used a laser lithography machine to create a prototype metabot 100 microns in height (a little thicker than a human hair). This type of metabot may one day help deliver drugs to specific areas in the body or assist in the repair of damaged bones or tissue. Other applications may include soft robotics, areospace engineering, energy absorption and spontaneous thermoregulation.
In the Terminator 2 movie the battle between Skynet and John Connor’s rebels takes place in 2029, we have a few short years to form the resistance.
Legless Jumping Robots
A team at Georgia Tech was inspired by a tiny jumping parasitic worm, a nematode, to create a 5 inch long soft robot that can jump 10 feet in the air (the height of a basketball hoop). Nematodes, also known as a round worm, are one of the most abundant creatures on Earth.
Nematodes live in the environment with humans, insects and animals. One way that they can latch onto their hosts is by jumping. The team used high speed cameras to record these jumps and learn how the nematodes bend their bodies into different shapes depending upon where they wanted to go.
To hop backwards nematodes point their head up while tightening the midpoint of their body. This creates a kink similar to someone doing a squat at the gym. The worm then uses stored energy to propel backwards, end over end like a gymnast doing a backflip.
To jump forward the worm points its head straight up and creates the kink not he opposite end of the body. Instead of hopping straight the worm jumps upward. The worm changes its center of mass to control which way they jump.
The team built soft robots that could replicate the worm’s leaping behavior. The robots were reinforced with carbon fibers to accelerate the jumps. The nematode uses the kinks to store energy and release the energy in a tenth of a millisecond in order to jump. They are able to repeat this process a number of times.
The team believes that they can create simple elastic systems made of carbon fibre or other materials that could withstand and exploit kinks to hop across various terrain. This might be very useful in a range of environments particularly on the moon and other planets where terrains will be different to those experienced on earth.
Engineered Metamaterials
The goal for engineering new metamaterials is usually stronger is better. The stronger the material created however the stiffer it will be. The stiffer the material the less flexible it is. MIT engineers have now found a way around this trade off.
The team have developed a way to fabricate a material that is both strong and stretchy. The base material is usually highly rigid and brittle however when it is printed in precise intricate patterns it forms a structure that is both strong and flexible.
The design is a combination of stiff microscopic struts and a softer woven architecture. This double network is printed using a plexiglass polymer and forms a material that can stretch to over 4 times its’ size without breaking. In other forms the same polymer has little to no stretch and shatters easily.
The same design may be able to be applied to fabricate different materials including stretchy ceramics, glass and metals. This could make tear resistant textiles, flexible semiconductors, electronic chip packaging and scaffolds for growing cells for tissue repair. Future ideas include making the materials conductive or responsive to temperature opening up a whole range of potential applications.
Air Driven Propellors for Ferries
A team from Sharjah University in the UAE have developed a method for using pneumatic propellers to replace diesel engines on a ferry. Each of the air motors developed generated 250 kilowatts and provided enough power to take ferries back and forth on a predetermined route in Finland’s maritime transport system.
Diesel Engines are the most reliable ICE engine in terms of power density, control and robustness however they are noisy, require large amounts of fuel and are highly polluting (Nitros Oxide and Nitric Oxide being among the worst of the pollutants).
Replacing Diesel Engines with pneumatic propellors is attractive from economic, practical and environmental objectives. Pneumatic propellors depend upon the power of compressed air to drive motors. Air is stored in tanks at high pressure and released into a vane air motor that is coupled with a naval impeller.
The team applied the new approach to an existing ferry in Finland. The predicability of pace, payload and destination of the ferry allows the replacement of the conventional diesel engines. The new system meet the same propulsion requirements as the diesel engine. The modular design offers scalability and can adapt to different operational needs.
The new system reduced fuel costs and lower maintenance. Replacing the engines had a payback period of 8 years. Future improvements in vane air motors will allow the use of more advanced materials and stronger pneumatic engines further reducing the payback period.
Paying it Forward
If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.
If you have any questions or comments please comment below.
I would also appreciate it if you could forward this newsletter to anyone that you think might be interested or provide a recommendation on Substack.