Issue link: https://iconnect007.uberflip.com/i/442619
22 The PCB Magazine • January 2015 is giving an aircraft or a car something resem- bling a nervous system. Structural electronics effectively takes no space because it is integrated into something that was already there, achiev- ing this by adding little weight to the integrated structure. However, in the world of electron- ics and electrics, the design rules change as we move from component selection and circuit design to functional de- sign. Product development has additional objectives. 3D printing may well prove to be the enabling tech- nology that brings structural electronics to the masses. For almost 30 years the 3D print- ing industry has viewed their technology through the eyes of the mechanical engineer. Hundreds of millions of dol- lars in R&D have been invest- ed in improving mechanical properties such as strength and precision. Only in the past three years has this begun to change. Two big names in the world of 3D printing, Stra- tasys and Optomec, collabo- rated on a project to assess the feasibility of using Optomec's aerosol jet technology to deposit not only conductive traces but even sensors onto the curved surfaces of an object 3D printed using thermoplastic extrusion by a Stra- tasys machine. The University of Warwick de- veloped the first usefully-conductive 3D print- able thermoplastic filament called Carbomorph and used it to 3D print flexible sensors. Google developed 3D printable conductive inks in col- laboration with 3D Systems for their modular mobile phone project and used them to 3D print computer-optimized antennas as part of the module shells. Inventables published an ar- ticle describing a simple way for hobbyists to prototype PCBs by injecting conducting pastes into channels within 3D printed parts. None of these techniques have caught on yet, but the momentum behind 3D printed electronics con- tinues to grow. To understand where 3D printed electronics might succeed it is necessary to first understand the applications of structural elec- tronics and the competing technologies that might solve the same problems. Modular wiring is perhaps the application closest to printed circuit boards. After all, tra- ditional PCBs have taken us a long way from using individual cables to connect everything. But wherever devices and equipment resort to using cables to connect PCBs there is the potential to provide a modular wiring solu- tion. For example, GE Health- care is the world's leading MRI scanner manufacturer and, despite the extensive use of PCBs in MRI machines, they have a lot of problems with wires. The wiring inside an MRI machine is not modular. A piece of MRI machine can- not be swapped out easily be- cause there are so many wires to disconnect, reconnect and test. 3D printed electronics might just be the ideal so- lution to this problem. The housing of the MRI machine could be 3D printed with all of the wiring integrated into it as conductive traces. The slow speed of 3D printing is a non- issue when you are manufacturing 100 devices per year. The ability to cost-effec- tively manufacture individual objects or runs of less than 1,000 would make a 3D printed elec- tronics solution the ideal platform for startups to launch new electronic devices such as Inter- net of Things or wearable devices. Although many more exciting applications of structural electronics exist none is perhaps as well suited to 3D printed electronics as modular wiring. Smart skin is another application of struc- tural electronics. Like a nervous system in a human body, sensor networks scattered across the body of a vehicle, such as an aircraft fuselage, will record and transmit essential data concerning the structural health of the vehicle. One solution is to turn the entire body of the vehicle into a printed circuit board. This idea is particularly popular in the aerospace industry OPPORTuNITIES FOR 3D PRINTED STRuCTuRAL ELECTRONICS continues a piece of mri machine cannot be swapped out easily because there are so many wires to disconnect, reconnect and test. 3D printed electronics might just be the ideal solution to this problem. the housing of the mri machine could be 3D printed with all of the wiring integrated into it as conductive traces. " " FEaturE