Inkjet-/3D-/4D-Printed Perpetual Electronics and Modules: RF and mm-Wave Devices for 5G+, IoT, Smart Agriculture, and Smart Cities Applications

With the revolutionary developments in the fields of millimeter-wave (mm-wave) and Internet of Things (IoT) technologies and the billion devices promised to be implemented by the end of the decade, the realization of inexpensive, low-power, and intelligent systems is highly desirable. Additive manufacturing (AM) is a technology seeing widespread adoption due to its ability to enable rapid prototyping for iterative design; its reduced setup costs, facilitating economic small-batch production; and its ability to significantly reduce waste by-products, resulting in both environmental benefits as well as lower manufacturing costs. On the other hand, current lithography-based manufacturing technologies-a huge contributor to the growing RF and 5G wireless electronics industry-require extensive design verification, have longer turnaround times, and produce harmful byproducts. Although AM can offer time and cost benefits under the correct conditions, among the more impactful demonstrations of the manufacturing technology are the novel topologies enabled by design rules that allow feature sets, including nonorthogonal planes, conformal surfaces, multimaterial deposition, simultaneous thick- and thin-film deposition [1], complex 3D structures, integrated voids, and gradient index materials.