Imec Electronics Stretches Like Skin
Research institute imec has integrated an ultra-thin, flexible chip with bendable and stretchable interconnects into a package that adapts dynamically to curving and bending surfaces.
The resulting circuitry can be embedded in medical and lifestyle applications where user comfort and unobtrusiveness is key, such as wearable health monitors or smart clothing.
At the 2012 ESTC conference (Electronics System Integration Technology Conference) in Amsterdam, taking place between September 17th and 20th, the researchers will present their results and showcase their latest demonstrations.
Today, most electronic appliances are rigid and mechanically flexible. A growing number of applications, however, require electronics that dynamically adapt to curving and bending surfaces.
For example, biomedical systems such as unobtrusive, wearable health monitors (e.g. electrocardiogram or temperature sensors), advanced surgical tools, or consumer electronics such as mobile phones embedded in smart textiles are needed.
Imec's associated lab at the University of Ghent has pioneered this technology and is inviting industrial partners to join the R&D program.
For the demonstration, the researchers thinned a commercially available microcontroller down to 30µm, preserving the electrical performance and functionality. This die was then embedded in a slim polyimide package (40-50µm thick).
Next, this ultrathin chip was integrated with stretchable electrical wiring. These were realised by patterning polyimide-supported meandering horseshoe-shaped wires, a technology developed and optimised at the lab.
Finally, the package was embedded in an elastomeric substrate, e.g. polydimethylsiloxane (PDMS). In this substrate, the conductors behave as two dimensional springs, enabling greater flexibility while preserving conductivity.
"Future electronic circuitry will stretch and bend like rubber or skin while preserving its conductivity," says Jan Vanfleteren, responsible for the research on flexible and stretchable electronics at imec's Ghent lab.
"This breakthrough achievement demonstrates that flexible Ultra-Thin Chip Packages (UTCP) can be integrated with stretchable wiring, paving the way toward fully flexible applications. We anticipate the first appliances will be used in intelligent clothing, with medical applications following later. Once commercial products are introduced, I expect to see clothing with signalisation by using LEDs and sensors to track movements."
This research is supported by the Agency for Innovation by Science and Technology in Flanders (IWT) through the SBO-BrainSTAR project.
