The next small big thing

The field of molecular engineering – involving the manipulation or creation of molecular structures – is one that is still in its infancy.

Indeed, to many engineers, the field is so contemporary that the work undertaken by the researchers involved in it might initially appear to have very little bearing on their own efforts solving more macroscopic problems using their expertise in mechanical, civil, electrical or electronic engineering.

Nothing, however, could be further than the truth. And one only has to look a little deeper into the efforts of a group of researchers working at Bristol University’s Centre for Complexity Sciences, School of Biological Sciences and the Departments of Biochemistry and Engineering Mathematics to see that this is indeed the case.

You see, the researchers there have developed a new type of soil fertility sensor that could one day be used by farmers to help them boost crop production without the use of lots of unnecessary fertilisers.

But this isn’t the sort of electronic sensor that you might pick out of an online catalogue from a respected distributor of electronic, electrical and industrial components such as RS Components, and then hook up to a microprocessor-controlled system to perform some analysis. Oh no. This particular sensor consists of a population of E-coli bacteria that has been modified to ‘detect’ the presence of a set of nutrients in the soil.

The researchers say that after growing the bacteria in quantity, they could then be sprayed across a newly ploughed field. Next, an ultraviolet light source fitted underneath a spreader pulled by a tractor would cause the modified bacteria to emit light if the nutrients in the soil were above a given threshold.

This light could then be detected by a camera that would work in a closed-loop control system to shut off the flow of fertiliser from the spreader whenever it is travelling over ground high in nutrients, hence reducing the amount of fertiliser needed to be spread over the field.

The researchers’ brilliant idea is clearly an indication of things to come. Indeed, there’s no doubt in my mind that such genetically engineered cellular systems are most certainly going to play an important role in many fields – not just fields in the countryside – over the next 100 years.

But let’s not forget that the complete system that the Bristol researchers propose also still depends on more established technologies that came before it. The tractor, the spreader, and the electronic systems that they carry will all need to work with the new technology to make it a viable solution.

And so too, I believe, will a lot of other systems just like it. The upshot is that those of us practising the older engineering disciplines won’t be out of a job just yet. Just the opposite, in fact – those folks working in the fields of molecular biology might just provide us with a whole bunch of new job opportunities.

Dave Wilson
Editor, Engineeringtalk

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