Bionics – the future of machinery design?
We observe a condor, all elegance and grace, soaring majestically in a cloudless sky. Its gigantic wings are awe-inspiring. Does it occur to anyone that the ends of these wings can be utilised as a principle for flight stabilisation?
In the case of modern-day aircraft, what are called “winglets“ are already in successful use.
We observe ant colonies, which organise themselves skilfully in order to travel from the food-gathering site back to the nest by the shortest route. Does it occur to anyone that this kind of thing can be calculated mathematically and that logistics companies are already benefiting from this?
Bionic researchers are giving this a lot of thought. Their task is to decode principles from nature and transfer them to the world of engineering. Anyone involved in design work can learn a lot from it. Because nature’s thinking is different.
Principles of engineering are often diametrically opposed to those of nature.
In engineering, lots of the work involved is performed with compressive forces. In nature with tensile forces.
In engineering, rotation motors are predominantly used. In nature, contraction motors.
In engineering, firm, stable outer shells are designed. In nature, encasements are light and yielding.
In engineering, constructions are straight-lined and angular. In nature, there are no angles or straight lines.
By comparing a bed with a hammock, we can clearly discern from a designer’s viewpoint the disparate approaches involved in terms of “conventional construction” versus “bionic design”.
Thanks to new manufacturing technologies, in the future the production of small batches will be more cost-efficient; restrictions in terms of shape are practically eliminated. This means that we will have to embrace the principles of nature in order to arrive at good solutions. And for this purpose there are innumerable approaches, of which birds’ wings and ants’ logistics are just two. Even the sexual organs of midges (tanytarsus sylvaticus) constitute a template for technical systems. This is the principle on which docking mechanisms of space shuttles are designed.
We are now going to perform a thought experiment. Today, we shall consider what a beverage filling line might look like in the future if it were to be designed on the principles of bionics.
Motors in nature
First of all, let’s look at drives. How does nature design motors? As I’ve already mentioned, engineering predominantly employs motors that drive by rotation. These are electric motors that with the aid of a coil convert electrical power into a rotary motion. In nature, however, motors drive by contraction. The heart is a motor of this kind. A muscle that pumps blood through the body by means of contraction. Here, atrioventricular and semilunar valves ensure that the blood flows in the right direction. A highly efficient and – in the truest sense of the word – long-lived motor, but different in design from an electric motor.
The outer skin of the bionic line is a membrane. Light and flexible.Otherwise, machines always have a rigid outer encasement. A steel envelope that has to be rigid enough to support itself. Machine guards are primarily intended to protect humans from reaching into rotating parts. A thin outer skin would suffice for this purpose. The skin of mammals, too, is one of these membrane constructions: it protects them against damage and temperature effects. In engineering, this principle is being used in BMW’s “GINA” concept. And the outer shell of the Allianz Arena in Munich is likewise a membrane construction. The world’s biggest membrane construction, in fact.
The shell of our bionic line of course possesses a dirt-repellent surface, featuring what is known as the “lotus effect”. Besides the archetypal lotus leaf, cabbage leaves also possess a water-repellent surface, featuring wax-coated, microscopically small unevennesses. Today, there are already easy-to-clean coatings like PTFE (Teflon) or the water-repellent “NanoSphere” textile, which makes use of the lotus effect.
In our line, cracks in the outer skin repair themselves, just as in nature wounds close of their own accord. Today, that is already the case with materials like “Biobeton” (“organic concrete”), which is able to knit together small cracks again. Or the inflatable, self-repairing support structure Tensairity®, which can be used to erect temporary bridges and roofs. Self-repairing foams prevent air from escaping if the membranes are damaged.
The supporting structure of our bionic line is modelled on the growth of trees. This avoids notch stress, and nonetheless only the absolutely necessary amount of material is used. This sounds as if it would entail a highly complex design. But it doesn’t.
This is because using the tensile triangle method of Prof. Dr. Claus Mattheck and the Research Centre in Karlsruhe, the growth of trees can be very simply reconstructed.
Nature swears by lightweight structures. Aesthetically appealing ones that we encounter in bones, in honeycombs and in water-lily leaves. Our line’s structure is skeletal in form. It’s the kind of structure that’s also found in radiolaria, single-celled water-dwellers with a beautiful, harmonious skeleton made of opal.
In our bionic line, the containers are transported to the individual modules by means of drones. Fish, bees, birds and ants – all these creatures are harmonised in shoals and swarms. In the case of forwarding agents, software developers model their approaches on ant colonies in order to ensure optimum trip planning. Because ants always find the shortest route when on the search for food, by marking the best possible path with pheromones. The first ants spontaneously choose a route, and the next ones then optimise it.
A bionic line
These themes are for the time being sufficient for us to design our bionic line: it basically looks like a collection of beehives. This is hardly surprising, since there are indubitably many associations between a beverage bottling line and a beehive. We have a process unit suspended from the ceiling, consisting of several different stations. These are driven by contraction motors. Drones transport the containers autonomously to the individual stations, at which they are filled, closed, and printed on. The stations’ outer shells are light, flexible membranes, reinforced by a hexagonal skeleton structure, featuring a filigree sponge structure inside.
So much for the thought experiment. But is this flight of fancy in fact so far removed from reality? The future is going to surprise us.