Additive Manufacturing

Case Study: Integrated Manufacture of Polymer and Conductive Tracks (IMPACT)

IMPACT is an InnovateUK funded project focused on the development of a new 5-axis 3D printing capability that is able to deposit polymer (using the Fuse Deposition Modelling process) and conductive ink within the same build volume. The 18 month programme, which was completed in March 2019, brought together a number of leading industry and academic partners that included: C Enterprise Ltd (CEL); Printed Electronics Ltd (PEL); Warwick Manufacturing Group (WMG); and ITERATE Design + Innovation. The output of this collaboration was an industrial grade platform capable of producing fully functional electro-mechanical parts 500 x 500 x 500 cm in size.

ITERATE worked alongside Ambionics to create a lower arm prosthetic that leveraged the capability of this new technology. Prosthetics are often difficult to manually assemble due to their complexity and are also weight critical. Prosthetics that are uncomfortable to wear, over sized or too heavy are rejected by the user. This prosthetic incorporated silver ink tracks, which removed the need for copper wires. Using a myro sensor connected to a linear actuator, the thumb opens and closes to create a firm grip when the user tenses a functional part of their arm, which is located inside the socket.

Through the undertaking of this project, ITERATE accumulated a vast amount of knowledge on how to design 3D printed polymer parts that integrate conductive tracks. This new technology has the capability to create fully functional electro-mechanical products straight off the machine bed. The 5-axis capability ensures that the parts created has a much higher structural integrity than those created on a traditional 3-axis machine. Whilst this project concentrated on producing a lower arm prosthetic, the potential for this technology to be applied across the aerospace, automotive, medical, consumer and industrial sectors is huge! To see the result of this project, please click here.

At the start of your 3D printing project it is important to consider the following factors:

• Function: Why do you want to build the product – do you want to ensure that a specific aspect of the design performs under load; do you want to test whether the product feels good to hold; or do you want the end-user to evaluate its aesthetic? These are just some examples but the purpose should be fully defined so that the most appropriate process, material and finish can be selected.
• Quantity: Due to the range of printing technologies available, the desired quantity should be determined. Processes such as FDM, SLA and SLS are ideal for building single or small batches. Large parts may take several hours to produce, whereas smaller components can be built within minutes. For those instances where 10s or 100s of parts are required, vacuum casting or soft tooling would offer a cost effective option.
• Material / Finish: These factors are critical if you are intending to gain end-user feedback. Parts that are low cost invariably have a poorer surface finish. These prototypes have their place but can distract the user from the product features you are trying to evaluate. It is possible to create demonstration pieces that mimic the aesthetic of the final product; however, if you are intending to simulate mechanical performance, material colour is very often limited.
• Budget: The benefit of 3D printing over many traditional manufacturing processes is that no initial investment/tooling is required. However, the unit cost will inevitably be higher when compared to mass production processes. The cost of your build can vary depending on the chosen process, quantity ordered and whether any post processing is required. Please contact us if you need help selecting an appropriate printing process or would like to obtain a quotation.