title: Ultra-sensitive Pressure sensor based on guided straight mechanical cracks.
abstract: Recently, a mechanical crack-based strain sensor with high sensitivity was proposed by producing free cracks via bending metal coated film with a known curvature. To further enhance sensitivity and controllability, a guided crack formation is needed. Herein, we demonstrate such a ultra-sensitive sensor based on the guided formation of straight mechanical cracks. The sensor has patterned holes on the surface of the device, which concentrate the stress near patterned holes leading to generate uniform cracks connecting the holes throughout the surface. We found that such a guided straight crack formation resulted in an exponential dependence of the resistance against the strain, overriding known linear or power law dependences. Consequently, the sensors are highly sensitive to pressure (with a sensitivity of over 1 × 105at pressures of 8-9.5 kPa range) as well as strain (with a gauge factor of over 2 × 106at strains of 0-10% range). A new theoretical model for the guided crack system has been suggested to be in a good agreement with experiments. Durability and reproducibility have been also confirmed.
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Yong Whan
authors.initials: YW
authors.lastname: Choi
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.|Department of Mechanical Engineering, Ajou University, San 5, Woncheon-dong, Yeongtong-gu, Suwon 443-749, Republic of Korea.
authors.forename: Daeshik
authors.initials: D
authors.lastname: Kang
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Pikhitsa
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Taemin
authors.initials: T
authors.lastname: Lee
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.|Department of Mechanical Engineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Sang Moon
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Gunhee
authors.initials: G
authors.lastname: Lee
authors.affiliation: Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Dongha
authors.initials: D
authors.lastname: Tahk
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Mansoo
authors.initials: M
authors.lastname: Choi