BAE Systems is investigating the use of techniques to print electronic circuits directly on to aerospace structures, reducing weight and increasing the amount of space available within aircraft.
The company is working with Airbus to study the potential capabilities of direct writing in military and civil aircraft. The technology uses techniques such as inkjet printing to deposit metallic and ceramic materials on to mechanical structures.
Electronic devices such as strain gauges and temperature sensors can be written directly on to aircraft surfaces, removing the need to place electronic circuits on to flat PCBs before fitting them to the aircraft, said Dr Jagjit Sidhu, research scientist at BAE’s Advanced Technology Centre at Filton.
‘It is about making better use of the structure, in terms of weight and space. PCBs contain a lot of chips and resistors, but most of the rest [of the board] is empty, so we want to make better use of the space,’ said Sidhu.
Devices such as strain gauges are currently attached to surfaces using adhesives, but by making a direct connection with the structure, the technology could potentially improve the accuracy of the data produced by the sensors, he said.
The industry is likely to begin making use of some elements of the technology in the next few years, although there are major issues that still need to be resolved, said Sidhu.
‘There are life cycle issues to be investigated, such as what happens if we need to repair a directly written component, and how they will cope in harsh environments.’
In the US researchers are investigating the possibility of printing batteries on to aircraft structures, said Brian Derby, professor of materials science at UMIST.
Rather than having a central power source for devices such as sensors, the batteries could be distributed around the aircraft with the sensors themselves, improving redundancy provision. ‘You could fit objects on to the wing, which would have their own local power source, and would communicate wirelessly,’ he said.
Ultimately circuits with radar-transparent properties would be printed on to aircraft structures, making the planes invisible to radar at certain frequencies.
Derby is investigating the use of inkjet printers to deposit silver – a highly conductive material – on to structures. But as with other metals silver has very different fluidic properties to standard inks, so he and his research team are attempting to gain a better understanding of these differences and the effect they have on the behaviour of the printer itself.
The North West Aerospace Alliance’s Aerospace Innovation Centre (AIC) recently held a seminar on direct writing. Dr Neil Calder, project innovator at the AIC, said the technology could be extremely important for the aerospace industry in the north west, which has traditionally been focused on producing ‘dumb’ aircraft components.
‘This is about getting a lot of functionality in a small space. We are adding functionality to what have previously been dumb structures,’ he said.