Additive manufacturing (AM), or 3D printing, is an enabling technology and is the future of manufacturing in a digital, local, low turnaround time, personalised world. Industry 4.0 aims to update manufacturing practice bringing it into the digital world through creativity, intelligence and connectivity. Direct digital manufacturing by allowing user access to 3D printing machines, is a key driver for industry 4.0, providing custom parts with rapid turn-around and reduced environmental impact. Designing, ordering, and delivery is now possible within 24 hours.

This expanding field has the potential to revolutionise many aspects of human life. The plastic and metal parts which can be manufactured through 3D printing can significantly reduce waste during the manufacturing process, as well as reduce the weight of parts shipped (reducing carbon emission for key sectors such as aerospace). These systems can also produce individually tailored parts for medical applications, such as orthopaedic implants, giving improved quality of life over a one size fits all approach.

Selective laser melting (SLM), is a leading AM process for making metal parts. Current SLM systems repeatedly deposit a layer of metal powder on a bed, then a high-power laser is scanned over the surface, melting only areas which require metal deposition on the layer below, akin to writing with a pen. This is repeated layer by layer, building a complete 3D structure. The SLM systems are expensive, and \\\>60% of the cost of the parts manufactured in this way are time dependant, holding back the deployment of these systems.

We will develop a rapid 3D printing technology using individually addressable direct diode (iADD) semiconductor laser arrays. The novelty in this work is the development of new laser systems based on photonic (light controlling) structures pattered on the nanoscale. These new laser arrays can allow an entire layer to be written in one go instead of one spot at a time. The full 3D parts can then be built between 4 to 10 times faster using our 1D array SLM system and between 10 and 100 times faster using our 2D array SLM system.

The lasers that produce the power to melt the powder require extensive lifetesting, which is essential to guarantee that the 3D printer is reliable and the parts made are robust.

We predict that this time and cost reduction will do for additive manufacturing what the printing press did for publishing.