Optimization of Spiral-based Structures for Stretchable Electronics

Nowadays we are very fortunate to be able to carry powerful computers in our pockets. This great achievement was the result of several decades of continuous evolution of the semiconductor industry with silicon as the leading material. However, looking further into the future, we foresee the rise of novel, exciting technologies, which not only will demand for higher electrical performance, in terms of data processing, storage, communication, etc., but also will introduce new mechanical demands. The electronics will have to be also compliant with asymmetric shapes and surfaces, for them to be adaptable, mobile, and capable of shape-shifting. In this way, for example, electronics could be now integrated with the human body and its mobile nature and therefore allow the growth of expanding technologies such wearable electronics and bio-integrated systems, among many others. The problem arises when we look at today's electronics, which although powerful, are based on rigid and brittle materials, still incompatible with the mechanical constrains of the technologies of the future. Many are trying to bridge this gap by innovative ways but there is still a lot to be done and explored. Organic materials, thinning, transfer printing, and others techniques have been used and developed for this purpose and although they show good levels of flexibility, they still fall short in delivering high enough electric performance. On the other hand, it has been demonstrated that especial designs and structural modifications can actually transform conventionally rigid materials (such silicon) into flexible and even stretchable platforms. Such is the case of serpentines, fractals, spirals among others geometries, which can potentially transform today's electronics into tomorrow's flexible and stretchable, high-performing electronics. I would like to aid in this exploration by improving the understanding of how to use innovative structural modifications in different kind of materials as platforms for flexible and stretchable electronics. With this aim, I will start with a comprehensive catalog of structures, geometric shapes and materials, adequate for the study, after which a finite element simulation will be performed to discover the main mechanical constrains of each of the structures/shapes. The stretching capabilities of each geometrical shape and material will be evaluated, depicting both stress and strain over the whole volume looking for potential week spots in the structures. After the compilation of all results, a complete comparison and analysis will be done to assess the best candidates to work as platform for future stretchable implementations of actual applications. Finally, a possible fabrication flow (based on available micro-fabrication and/or micro-machining techniques) will be proposed based on the best resulting structures and materials. Lastly, this study will be summarized in a conference paper and a journal paper, which can be then the foundation for a stronger paper with the actual fabricated and demonstrated structures and even devices. Although the nature of the project remains exploratory, it is an essential step towards future real products and can help to build the foundation for a complete novel technology, which it is what stretchable electronics represents.