Suspended bimaterial microchannel resonators for thermal sensing of local heat generation in liquid

• Published in: Microsystem technologies : sensors, actuators, systems integration Vol. 19; no. 7; pp. 1049 - 1054
• Main Authors: Toda, Masaya, Otake, Tomoyuki, Miyashita, Hidetoshi, Kawai, Yusuke, Ono, Takahito
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2013; Springer
• Subjects: Applied sciences; Electronics; Electronics and Microelectronics; Engineering; Exact sciences and technology; Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials; Mechanical Engineering; Mechanical instruments, equipment and techniques; Micro- and nanoelectromechanical devices (mems/nems); Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Nanotechnology; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Technical Paper; Resonant Frequency; XeF2; Suspended Bridge; Triple Layer; Microfluidic Channel; Water; Resonator; Bridge circuit; Solid solid interface; Thermal behavior; Resonant structure; Thermal properties; Silicon on insulator technology; Heat source; Buried channel; Tensile stress; Lamellar structure; Laser beam; Silicon oxides; Resonance frequency; Molecular biology; Microelectromechanical device; Wafer; Heterostructures; Microfluidics; Fluidics; Production process
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-012-1698-3

Suspended bimaterial microchannel resonator devices have been fabricated to measure the thermal behaviors of small biological molecules and individual cells in liquid. A resonant microbridge structure embeds this microfluidic channel in its interior. The fabrication process is based on the creation of buried channels in silicon-on-insulator wafers. For the bimaterial bridge structure layers of SiO 2 and SiN x were used. This bimaterial resonant bridge with internal microfluidic channel could be employed as a very sensitive calorimeter, since the tensile stress generated by bimaterial effect in the heated bridge, produces a shift of resonant frequency. A laser beam was used to heat the center of the bridge resonator with the microchannel filled by water and the corresponding resonant frequency variations were evaluated. The measured sensitivity for the local heat at the center of the bridge is 8.6 ppm/μW in atmospheric condition.