Inkjet printers used for explosives

January 18, 2018

Inkjet-printed nanothermite. (Picture: Jared Pike, Purdue University)

Research at a US university has shown how inkjet printing can aid the creation of tiny explosives.

A team of researchers at Purdue University, Indiana, have developed a way to print small quantities of explosives using an inkjet printer, reports The Register. The tiny explosions could have many practical, everyday uses, such as being deployed to set off car airbags in the event of a crash.

The group of scientists successfully used additive manufacturing to blend and print so-called ‘energetic materials’ (such as propellants, pyrotechnics and explosives) using inkjet technology. The material is created from inert suspensions of copper and aluminium – which reduces the chances of spontaneous explosion; the aluminium provides the fuel, and the copper oxide, the oxidiser.

“We can have a fuel and an oxidiser in two separate suspensions, which are largely inert,” explained Professor Jeff Rhoads. “Then, with this custom inkjet printer, we can deposit the two in a specific overlapping pattern, combining them on a substrate to form nanothermite” – nanothermite being one such ‘energetic material’.

Rhoads went on to say that the hardest part of the development was retaining the right mix of ingredients, whilst dealing with picolitres – tiny quantities of material, equivalent to a thousand cubic micrometres. However, the use of an inkjet printer for the template provided accuracy to within 0.1 millionths of a metre.

Other members of the research team working on the project included Alison Murray, George Chiu, Emre Gunduz, and Steve Son.