Stretchable and flexible electronics are often referred to as the same thing. They are smart devices built on stretchable films, which can be used to make, for instance, wearable electronics or stretchable industrial components such as sensors and cables. Wearable electronics, i.e. smart clothing, have been predicted to have significant global growth potential, but despite decades of development, their use has not become commonplace.
“The separate development of technologies, even at the standardisation level, has limited and slowed down the development of stretchable electronics and smart clothing,” Teemu Salo says.
Solutions for combining hard and stretchable materials
Stretchable electronics consist of three components: a stretchable substrate, stretchable conductors, and hard but small printed circuit board (PCB) modules. When integrating stretchable electronics into, for example, clothing, the electronics structure must adapt to the movements of the substrate. Materials of components and manufacturing and assembly methods can be used to ensure that, for instance, the stretching of smart clothing in use does not damage the structures and properties of the integrated electronics system.
“The system is stretchable despite the hard PCB modules. The PCB modules are distributed on the substrate as islands and connected electrically by stretchable conductors. The challenge of the structure is the uneven distribution of strain, which prematurely breaks the electrical functions. Controlling strain locally is a prerequisite for durable stretchable electronics and smart clothing,” says Salo.
His doctoral thesis will explore manufacturing methods for stretchable electronics and investigate local strain control by modifying the shape of PCB modules and 3D printing support structures for stretchable conductors. He shows that 3D printing is suitable not only for the fabrication of support structures but also for the manufacture of stretchable conductors and sensors.
“By combining current stretchable electronics manufacturing methods and 3D printing, hybrid structures can be made that will enable the development of smarter and more durable next-generation wearable electronics,” Salo explains.
Dissertation on Thursday 28 March
The doctoral dissertation of M.Sc. (Tech.) Teemu Salo in the field of electronics titled 3D Printing and Stretchable Electronics will be publicly examined at the Faculty of Information Technology and Communication Sciences at Tampere University in room TB109 of the Tietotalo building (Korkeakoulunkatu 1, Tampere) at 12:00 on Thursday 28 March 2024.
The opponent will be Research Professor Jussi Hiltunen from VTT. The custos will be Professor Jukka Vanhala from the Faculty of Information Technology and Communication Sciences, Tampere University