TY - DATA T1 - micromachines-08-00277.pdf PY - 2017/09/13 AU - salman shafqat AU - Johan P. M. Hoefnagels AU - Angel Savov AU - Shivani Joshi AU - Ronald Dekker AU - Marc G. D. Geers UR - https://figshare.com/articles/journal_contribution/micromachines-08-00277_pdf/5404561 DO - 10.6084/m9.figshare.5404561.v1 L4 - https://ndownloader.figshare.com/files/9310954 L4 - https://ndownloader.figshare.com/files/9310957 L4 - https://ndownloader.figshare.com/files/9310960 KW - Stretchable Electronics KW - Ultra-stretchability KW - CMOS processing KW - Size-effects KW - Miniature interconnects KW - Microfabrication KW - Freestanding interconnects KW - Extreme stretchability KW - Microelectronics KW - Soft electronics KW - Flexible electronics KW - Balloon catheter KW - Small-scale testing KW - Mechanical Engineering N2 - The exciting field of stretchable electronics (SE) promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS)-type) process recipes using bulk integrated circuit (IC) microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS type batch processing is assured by utilizing the Flex-to-Rigid (F2R) post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic) stretch beyond 3000%, with <0.3% resistance change, and >10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly stretchable miniature devices. ER -