Progress with stretchable electronics

Stretchable electronics is needed for many potential applications in healthcare and elsewhere. It was covered in the recent conference "Printed Electronics Europe" in Dresden, Europe's largest conference and exhibition on the subject. In particular, the presentation "Skin-like electronics: fabrication of thin-film devices with ultra-low temperature process" by Ingrid Graz of the Nanoscience Centre, University of Cambridge UK describing her work with Stéphanie P. Lacour on this topic was very well received.

She gave three related objectives:

Electronics that can be shaped

Source: S.P.Lacour

Electronics that can be stretched

Source: S.P.Lacour

and electronics that can be interfaced with biological tissue.

Source: B. Morisson et al

She pointed to potential applications at the human-machine interface and on and in the human body, from fashion and e-textiles to prosthetic skin and even neural interfaces. Sometimes it is useful if the device stretches but returns to its original form.

Source: S.P.Lacour

Routes being investigated include:

Integrating hard electronic devices on highly compliant substrates
Using available planar technology with a bottom up fabrication approach
Selecting ultra-low temperature process
Designing carefully the mechanical architecture of the stretchable electronic system
For example, on metal coated stretchable polymer, metal film may elongate reversibly due to out-of-plane deformation.

Source: S.P.Lacour

In some of the work, the polymer film is stretched before it is metal coated. Piezolelectric like embedded elements in PDMS have been studied. They have demonstrated thin-film devices integrated on elastomers, stretchable metallic conductors, stretchable circuits that rely on interconnect stretchability and 'protected' rigid devices.