ADDITIVE MANUFACTURING
Rafal Walczak
Wroclaw University of Science and Technology, POLAND

Abstract
Additive manufacturing, commonly known as three-dimensional (3D) printing or rapid prototyping, has been introduced since the late 1980s. Although a considerable amount of progress has been made in this field, there is still a lot of research work to be done in order to overcome the various challenges remained and fully utilize advantages of 3D printing. Recently, one of the actively researched areas lies in the additive manufacturing of integrated systems composed with mechanic and electronic elements towards new generation of sensors and transducers. 3D printing enables the creation of complex geometric shapes and merging of selected functional components into any configuration, thus supplying a new approach for the fabrication of multifunctional end-use devices that can potentially combine optical, chemical, electronic, electromagnetic, fluidic, thermal and acoustic features. On the other hand, natural tendency in development of emerging technologies as 3D printing of sensors and transducers is, research on limits of the technology and new potential fields of applicability including combination of micromechanic and microelectronic systems. These issues are both present in development of very small (down to micrometer scale) mechatronics systems called micromechatronic systems or Micro-Electro-Mechanical Systems (MEMS). MEMS integrates various mechanical structures that forms sensors or transducers (in case of this presentation vibrational sensors and energy harvesters) that co-works with integrated or external electronic or optoelectronic circuits. In case of MEMS made of silicon, glass, metal or polymers typical microengineering or precise mechanic technologies are applied. These technologies are time consuming, multistep, expensive, require sophisticated equipment and special laboratories (clean-rooms). Also geometry of the fabricated structure is often limited by the applied tools and initial form of the processed material or substrate (wafer). Printing MEMS is a new approach that requires comprehensive studies on 3D printing of very small mechanic structures with tailored mechanical properties as key components of integrated miniature transducers or energy harvesters. Also new strategies of MEMS structures fabrication involving unique properties of various 3D printing techniques must be taken into account.

The presentation will describe selected techniques of 3D printing useful from the point of view of MEMS and power MEMS development. Principles of operations, main properties, limitations and examples of fabricated microstructures will be discussed. Some of 3D printed power MEMS developed by Walczak's group will be presented as examples of successful application of various 3D printing techniques.

Bio
Rafal Walczak is the Dean of the Faculty of Electronics, Photonics and Microsystems of Wroclaw University of Science and Technology. He was/is leading researcher of many Polish and international (EU Framework Programmes) scientific projects related to development of various silicon, glass and polymer devices utilizing micro/nanotechnologies and emerging technologies, including lab-on-a-chip and 3D printed microsystems energy harvesters. He is author and co-author of over 200 scientific papers. During his career he has attended more than 100 conference and schools, he has more than 50 oral communications at conferences. He received also many conference awards for outstanding oral and poster presentations and national prestigious awards including Defender 2014 Award of Internationals Defence Industry Exhibition and 2014 Golden Laure of National Technical Organisation. He is member of Executive Board of Polish Society of Sensor Techniques, member of International Steering Committee of Eurosensors Conference and he was member of MANCEF Foundation General Advisory Board. He was co-chair of Power MEMS 2019 conference.