Research laboratory Imec has announced that it 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.
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 realized by patterning polyimide-supported meandering horseshoe-shaped wires, a technology developed and optimized at the lab. Last, the package is 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.