Issue link: https://iconnect007.uberflip.com/i/324117
22 The PCB Magazine • June 2014 F e a t u r e Reproduced with permission from Journal of Applied Physics. Copyright 2014, AIP Publishing LLC. Abstract When rigid and stretchable components are integrated onto a single elastic carrier sub- strate, large strain heterogeneities appear in the vicinity of the deformable-non-deformable in- terfaces. In this paper, we report on a generic approach to manufacture hybrid stretchable cir- cuits where commercial electronic components can be mounted on a stretchable circuit board. Similar to printed circuit board development, the components are electrically bonded on the elastic substrate and interconnected with stretchable electrical traces. The substrate—a silicone matrix carrying concentric rigid disks— ensures both the circuit elasticity and the me- chanical integrity of the most fragile materials. Stretchable electronics is a fast emerging field that provides radically new form factors to electronic circuits [1] . Some of the most excit- ing applications include novel human-machine interfaces in the form of skin-like [2–6] or epider- mal circuitry [7,8] and bioelectronic monitoring [9] . The main requirement for stretchable circuits is that the electronic devices and circuit perfor- mance do not, or only predictably, change with the applied mechanical loading. One approach to manufacture stretchable circuits is to produce a stretchable circuit board onto which standard, off- the-shelf components may be mounted [10,11] . Rigid component islands are distributed on the surface of an elastomeric substrate and interconnected with elastic wir- ing. This hard-on-soft integration however suf- fers from large mechanical strain concentration at the interface between the rigid (PCB-like) islands and the stretchable substrate. Because interconnects must run across these interfaces, early electrical failure of the stretchable circuit is often observed [12] . This paper presents a simple solution to this challenge and demonstrates a functional hybrid stretchable circuit fabricated on an engineered stretchable circuit board. The latter is designed so that non-deformable regions are embedded within the elastomeric substrate (rather than by A. Robinson, A. Aziz, Q. Liu, Z. Suo, and S. P. Lacour Hybrid Stretchable Circuits on Silicone Substrate