From nuclear decommissioning to drone design, engineers are taking inspiration from nature

Bio-inspired engineering has grown in profile in recent times, and is getting used to deal with historically intractable issues, as Envirotec found.

Engineers have been borrowing concepts from nature for a very long time. Leonardo da Vinci’s ornithopter flying machines – primarily based on observations of birds – are a basic instance. It took some time for engineers to understand there have been simpler methods to launch a machine into the air than flapping a set of wings, however we received there ultimately.

Such has been the connection between these two domains: not a trouble-free marriage by any means, however an more and more fruitful one. Latest a long time have seen its formalization as a definite department in engineering.

A latest discuss on the topic by Professor Adam Stokes conveyed a few of the pleasure and sense of risk the sector is at present producing, and showcased examples of the work being undertaken by his personal Tender Programs Group, a part of the Institute for Built-in Micro and Nano Programs in The College of Engineering at The College of Edinburgh.¹

Stokes’ title of “Private Chair in Bioinspired Engineering” is a nod to the fields’ rising recognition. His personal multi-disciplinary pedigree – with a CV buttressed by a minimum of three undergraduate levels (in biomedical sciences, engineering and chemistry) – hints at its huge breadth, and inherent challenges.

Biology and engineering appear to face aside, as approaches to understanding the world. The distinction is breezily summed up by Professor Julian Vincent of Heriot-Watt College in a latest paper, with the statement that engineering is numerate, whereas biology is descriptive.

However a tangled provenance is undisputed: Electrical engineering, for instance, has its origins in statement of the pure world, and the electrical energy current within the nervous techniques of animals.

Stokes’ discuss contrasted the 2 fields at one level with a slide displaying an octopus tentacle subsequent to a six-axis robotic arm – exemplars, maybe, of their respective domains’ makes an attempt to grapple with the world.

Engineers typically construct issues utilizing elements or sub-systems (like motors and rotary encoders) and in a fashion that affords excessive precision and accuracy. It’s an method that has yielded helpful machines for performing uninteresting, repetitive jobs, and which may work in harmful or inhospitable environments, as he defined.

However you possibly can’t construct an octopus tentacle like that. The accessible sub-systems – motors and encoders, for instance – can’t probably match the ambition and class displayed by this technique. And only for good measure Stokes confirmed a video of an octopus squeezing by a tiny gap the scale of a ten pence piece.

“As an engineer, I don’t know the way to do that,” he stated, including that you could’t construct one thing like this from motors and encoders. “What’s it nature is doing that we’re not capable of do? How can we copy it?”

Slightly than merely counting on serendipity or open-ended brainstorming, latest years have seen developments in direction of a extra disciplined method. Julian Vincent, for instance, has popularized strategies like TRIZ (Concept of Creative Drawback Fixing) on this discipline. TRIZ works with a set of 40 “creative rules” – a finite checklist that purports to characterize the accessible methods of fixing issues.

He has constructed a database of the methods biology has managed to resolve totally different issues – or “tradeoffs”, particularly (for instance, velocity vs accuracy, energy vs weight, and so forth). Builders on this discipline can search the database when in want of inspiration. As Stokes defined, so long as you possibly can phrase the issue appropriately, Julian can set off concepts about the way to resolve it.

A flying begin
One downside that nature appears to have solved, for instance, is the power to stay airborne with out a lot vitality or effort – exemplified by pure flyers comparable to dandelion fruit. By finding out this pure functionality, one venture – referred to as “Dandidrone: A Dandelion-Impressed Drone for Swarm Sensing” – hopes to beat a few of the challenges of utilizing airborne sensors to watch pure disasters or different inaccessible websites.

Latest work has proven that the porous wing of the dandelion results in the formation of a fluid vortex, by no means beforehand noticed. As an outline on the venture’s web site places it, the purpose is “to unveil the underlying fluid mechanics mechanisms that enable the dandelion to stay airborne by exploiting the vitality within the wind.”

The mathematical underpinning of a lot of right now’s sensible robotics is the Jacobian matrix, which permits engineers to map inputs to outputs, and thereby describe (mathematically) the behaviour of a management system like a robotic arm.

A system like a six-axis robotic arm will probably be describable utilizing matrix calculations. The 2 distinct actions of rotation and translation (i.e., shifting an object from one place to a different) will be encapsulated in mathematical phrases by matrices for rotation and translation, respectively.

Tender robotics brings in two further matrices to explain scaling (i.e., what occurs when one thing modifications measurement) and shearing (i.e., when objects change form however not measurement, as when a sq. turns into a parallelogram). These sorts of actions introduce the brand new functionality for interplay – which, as Stokes places it, “may be very possible the reply to the query: ‘What do we wish delicate techniques to do?’”

Do be delicate
With the ability to work together with the world opens the door for robots to supply assist with care-giving and related roles. One member of the group not too long ago gained a Scottish Edge award of £80k for his firm, Konpanion, which gives a delicate robotic machine that’s meant to assist folks fight loneliness and anxiousness.

One other firm licenses the Edinburgh group’s patents to make grippers utilized in meals processing – for dealing with merchandise like seafood and rooster. The compliance (i.e., softness) of those grippers removes the necessity for precision, so the grippers can transfer very quickly and seize a bit extra wildly at an object. It’s a lot easier than the choice choice of utilizing suction gadgets, which additionally current a necessity for normal disinfection and cleansing as a result of the open gasoline line sucks in bits of meals and particles.

Constructing these sorts of techniques appears to proceed alongside much less deterministic strains than conventional robotics, the place secure, recognized elements give rise to predictable behaviour on the system stage. Constructing delicate robots includes extra of a “let’s see what occurs” method, in Stokes’ telling. And the emergent behaviour will be attention-grabbing and sophisticated, with potential utility that solely turns into obvious after you’ve tried it.

Stokes gave examples comparable to the usage of a easy balloon actuator. It may be constrained alongside one axis in order that, when it inflates, it does so alongside one aspect greater than the opposite. This can be utilized to create a robotic with one thing like a again and 4 legs, which may stroll round, and even do issues like flattening right down to limbo beneath a slender hole.

When Stokes’ group first submitted these sorts of experiments to journals, about 12 years in the past, one of many first feedback to come back again was “I don’t know what that is, however it’s not robotics.” Since then, he stated, the sector has grown, and there at the moment are worldwide conferences about delicate robotics, and tens of hundreds of individuals working within the discipline.

Tender actuators additionally appear draw upon fairly totally different supplies to conventional robotics, together with fluids, form reminiscence alloys, and electro-active polymers. Though Stokes’ pleasure additionally appeared to derive from the potential of utilizing low cost, disposable supplies – and this additionally modifications the use case of robotics, introducing the likelihood that it may be disposable. His personal group has constructed robots from balloons, rubber bands and ingesting straws, picked up from a neighborhood newsagent.

“Why? I don’t know,” he stated. “Generally it’s worthwhile doing issues as a result of they’re attention-grabbing.” You possibly can decide the utility as soon as it’s been constructed.

Curiously, he stated, these are additionally robotic techniques that may’t be simulated, involving as they do, issues like complicated thermodynamics within the compression of a gasoline, the complicated properties of various elastomers (and the way they behave beneath pressure) and so forth.

And it’s within the emergent properties the place the helpful behaviours seem, the stuff that may have some usefulness. One video throughout his discuss confirmed a starfish-like plastic robotic that realized to kick a ball. Slightly than a design method the place you’re specifying a exact motion in area for an finish effector (like a robotic foot), you possibly can enable the system to work out the way to do it. On this case the robotic may very well be requested to kick a ball, and to take action in probably the most environment friendly approach. The venture mixed robotics, AI and reinforcement studying.

Novel supplies appear to be an enabler. One focus of latest experimentation is the usage of actuators that characteristic a steady circulate of fluid inside the construction, in a closed-loop system. This enables very particular deformations of the fabric, and a excessive stage of flexibility and flexibility within the actuator – an advance on circulate actuators that merely use a cyclic or rhythmic circulate of air or liquid.

The group at Edinburgh has been working with “Fluidic Flowbots”, which exploit this sort of steady fluid circulate. They usually have proven that complicated robotic behaviours will be designed with a a lot easier management structure. A latest paper demonstrates issues like a bidirectional actuator, a gripper and a quadruped swimmer.

The design will be a lot easier as a result of complicated motion doesn’t essentially require complicated enter or processing, not like in standard robotics the place the whole lot scales linearly (i.e. in case you transfer from having 5 actuators to having 1,000, you’ll require 1,000 management strains, 1,000 transistors and so forth). Nature doesn’t construct issues on this approach – in different phrases, with the management system and the embodiment constructed individually. In nature these items are intrinsically blended with one another. “Nature does a very good job of hiding complexity,” he stated at one level.

This sort of delicate robotics will be constructed from one materials, with out shifting elements, and might even be biodegradable, stated Stokes, holding forth the likelihood for techniques to be transient, and able to being left to carry out an motion in an atmosphere like the ocean, and allowed to biodegrade.

Hydraulic logic
These fluidic techniques may also be used to construct circuits that carry out the identical capabilities as computing or digital logic – for instance, logic gates, reminiscence processors and the like. Stokes stated these elements “will be stacked collectively and embedded inside these delicate machines”. On this approach, you possibly can construct techniques with electronics-like performance however with none precise electronics, and even metals. Such techniques can be utilized in locations the place there’s a excessive threat of explosion, or the place there are very excessive magnetic fields (inside MRI machines, for instance), or the place there’s a excessive stage of radiation.

Nuclear decommissioning is one utility the place delicate robotics can fulfil an pressing want. In locations just like the Fukushima Daiichi Unit 2 Reactor, standard discipline robotics is required to hold out important upkeep duties, utilizing costly and complex gear with a lifespan severely restricted by the excessive ranges of radiation. A lot of its time is preoccupied with the processor-hungry enterprise of merely navigating from level to level, with all of the difficulties of robotic navigation in an unstructured atmosphere.

As an alternative of utilizing standard robotics (primarily based on electronics), a venture referred to as Join-R is utilizing a system the place the whole lot inside is hydraulic. Modular robots construct a cubic construction out of discrete blocks – a sort of “3-D Scalextric observe in free area”, as Stokes places it – which may then go energy and knowledge to the totally different elements of the system. Small robots can transfer alongside tracks within the construction – utilizing a standardised and easy type of locomotion – and carry out duties, with out having to spend time planning the way to get from one place to a different.

Join-R is a flagship venture funded by Innovate UK, and undertaken by a partnership of business, authorities and academia (together with the College of Edinburgh and Royal Holloway College of London).

The way forward for robotics will probably be in hybrids, stated Stokes, which mix parts of laborious and delicate robotics. Arduous is greatest for exact positioning whereas delicate robotics brings in alternatives for compliance (i.e., with the floor of one other object), in addition to velocity and low price.

Notes
[1] The discuss “Following Nature’s Lead: Bio-inspired Applied sciences” was given on fifth December 2023 on the College of Strathclyde, an occasion organised by The Establishment of Engineers in Scotland (IES). See https://engineers.scot/occasions/.