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In the past 15 years stretchable electronic circuits have emerged as a new technology in the domain of assembly, interconnections and sensor circuits and assembly technologies. In the meantime a wide variety of processes with the use of many different materials have been explored in this new field. The purpose of the current contribution is for the authors to present an approach for stretchable circuits which is inspired by conventional rigid and flexible printed circuit board (PCB) technology. Two variants of this technology are presented: stretchable circuit board (SCB) and stretchable mould interconnect (SMI).

Similarly as in PCB 17 or 35 μm thick sheets of electrodeposited or rolled‐annealed Cu are structured to form the conductive tracks, and off‐the‐shelf, standard packaged, rigid components are assembled on the Cu contact pads using lead‐free solder materials and reflow processes. Stretchability is obtained by shaping the Cu tracks not as straight lines, like in normal PCB design, but as horseshoe shaped meanders. Instead of rigid or flexible board materials, elastic materials, predominantly PDMS (polydimethylsiloxane), are used to embed the conductors and the components, thus serving as circuit carrier. The authors include some mechanical modeling and design considerations, aimed at the optimization of the build‐up and combination of elastic, flexible and rigid materials towards minimal stress and maximum mechanical reliability in the structures. Furthermore, details on the two production processes are given, reliability findings are summarised, and a number of functional demonstrators, realized with the technologies, are described.

Key conclusions of the work are that: supporting the metal meanders with a flexible carrier prior to embedding in an elastic substrate substantially increases the reliability under mechanical stress (cyclic uniaxial stretching) of the stretchable interconnect and the transition areas between rigid components and stretchable interconnects are the zones which are most sensitive to failure under mechanical stress. Careful design and technology implementation is necessary, providing a gradual transition from rigid to flexible to stretchable parts of the circuit.

Technologies for stretchable circuits, with the same level of similarity to standard PCB manufacturing and assembly, and thus with the same high potential for transfer to an industrial environment and for mass production, have not been shown before.

The purpose of this paper is to show the evolution of microsystems together with modeling methods in the space of dozen years as a result of finished research in the frame of several projects.

In this paper several approaches are presented. First, microsystems were built in multi project wafer technology. They were demonstrators like micromotor, micromirrors or micropumps modeled using dedicated design tool. A multi purpose chip was also designed using HDL description and FEM simulations. The next project concerned chemical sensors, where specialized models were developed and implemented in VHDL‐AMS in order to perform multidomain behavioral simulations. Dedicated tools were also developed for medical applications.

The evolution of MEMS technology is strictly connected with simulation and modeling methods. The success and short time to market need fast and accurate simulation methods. This paper shows that the approach depends on application. Moreover, it is connected with the access to the technology.

This paper presents a brief overview on projects performed in DMCS‐TUL department. It shows the evolution of modeling methods and technology used in developing and fabrication of microsystems for various applications.