Symmetrical and decoupled nickel microgyroscope on insulating substrate

Alper, Se
Akın, Tayfun
This paper presents a symmetrical and decoupled surface micromachined gyroscope fabricated by electroforming thick nickel on a glass substrate. The symmetric structure allows matched resonant frequencies for the drive and sense vibration modes for improved sensitivity, while the decoupled drive and sense oscillation modes prevents unstable operation due to mechanical coupling, resulting in a low zero-rate output drift. The use of a glass substrate instead of a silicon substrate reduces noise due to the parasitic signal coupling by two orders of magnitude, according to both simulation results in CoventorWare and measured results on fabricated devices. A capacitive interface circuit which is fabricated in a 0.8 mum CMOS process is hybrid connected to the gyroscope, where the circuit has an input capacitance lower than 50 fF and a sensitivity of 33 mV/fF, which are currently limited by the parasitic capacitances due to hybrid wirebonding. It has been identified that the amount of parasitic capacitances must be lower than or at least in the same order with the electrical equivalent capacitance of the gyroscope for clear mechanical resonance characteristics to be obtained. Fabricated gyroscopes have close resonant frequencies for the drive and sense modes, as 37.2 and 38.3 kHz, respectively. Calculations on measured resonance values suggest that the fabricated gyroscope with 16 mum-thick structural layer provides a Brownian noise floor of 7.3degrees/h/Hz(1/2) at vacuum. Currently, the overall rate sensitivity of the gyroscope is limited to 96degrees/h in 50 Hz bandwidth for matched-frequency operation, and it can be decreased down to 56degrees/h in 50 Hz bandwidth, by improving the quality of the electrodeposited nickel.


Design of a microbial sensor using conducting polymer of 4-(2,5-di(thiophen-2-yl)-1H-pyrrole-1-l) benzenamine
Tuncagil, Sevinc; ODACI DEMİRKOL, DİLEK; Yidiz, Ersin; TİMUR, SUNA; Toppare, Levent Kamil (Elsevier BV, 2009-03-28)
A microbial biosensor based on Gluconobacter oxydans cells immobilized on the conducting polymer of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine (SNS-NH2) coated onto the Surface of graphite electrode was constructed. The proposed biosensor was characterized using glucose as the Substrate. The linear relation was observed in the range of 0.1-2.5 mM and defined by the equation y = 0.415x + 0.377 (R-2 = 0.986). Analytical characterization, effects of electropolymerization time, pH, cell amount and the ...
A low-cost rate-grade nickel microgyroscope
Alper, Said Emre; Silay, Kanber Mithat; Akın, Tayfun (Elsevier BV, 2006-11-08)
This paper presents a low-cost microgyroscope with a resolution in the rate-grade at atmospheric pressure, which is fabricated using a CMOScompatible nickel electrofonning process. Angular rate resolution of the gyroscope is increased by matching the resonance frequencies of the drive and sense modes close to each other using symmetric suspensions and electrostatic frequency tuning; whereas, undesired mechanical coupling between the two modes during matched mode operation is reduced by the fully decoupled g...
A sol-gel derived AgCl photochromic coating on glass for SERS chemical sensor application
Volkan, Mürvet; Vo-Dinh, T (Elsevier BV, 2005-05-13)
A new optically translucent material has been prepared that acts as a substrate for surface-enhanced Raman spectroscopy. This material is a silica matrix, synthesized by the sol-gel method and containing in situ precipitated AgCl particles which serve as precursors for nanoparticles of elemental silver. Reduction of AgCl to silver nanoparticles is achieved by UV irradiation. The SERS-active medium was distributed on glass supports (cover glass slips, 0.5 turn thick), hence producing thin, sturdy, and optica...
Tunable dual-frequency RF MEMS rectangular slot ring antenna
Topalli, Kagan; Erdil, Emre; Aydın Çivi, Hatice Özlem; Demir, Şimşek; Koç, Seyit Sencer; Akın, Tayfun (Elsevier BV, 2009-12-01)
This paper presents the design, fabrication, and measurement of a novel, tunable, dual frequency rectangular slot antenna using RF MEMS technology. The antenna tuning is achieved by electrostatically actuated RF MEMS variable capacitors on a stub. Two different capacitor structures are implemented on the antenna: cantilever type and fixed-fixed beam type. The latter one is not sensitive to the stress on the structural layer and its measurement results agree well with the simulation results. Each antenna is ...
Atomic and electronic structure of rigid carbon atomic chains
Usanmaz, D.; Srivastava, G. P. (Wiley, 2012-09-01)
We have reported, from ab initio calculations, on the changes in the electronic and structural properties of short carbon atomic chains held rigidly between hydrogenated armchair graphene nanoribbons (AGNR) and zig-zag graphene nanoribbons (ZGNR). Several lengths (N?=?29 atoms) and forms of the chains have been considered. All models are found to be metallic in nature, with chemical bonding more like $\cdots {\rm C}- {\rm C}\equiv {\rm C}- {\rm C}\equiv {\rm C}\cdots $ (as in polyyne) for odd-numbered chain...
Citation Formats
S. Alper and T. Akın, “Symmetrical and decoupled nickel microgyroscope on insulating substrate,” SENSORS AND ACTUATORS A-PHYSICAL, pp. 336–350, 2004, Accessed: 00, 2020. [Online]. Available: