Tomi Mattila

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Nonlinear effects in single-crystal silicon microresonators are analyzed with the focus on mechanical nonlinearities. The bulk acoustic wave (BAW) resonators are shown to have orders-of-magnitude higher energy storage capability than flexural beam resonators. The bifurcation point for the silicon BAW resonators is measured and the maximum vibration(More)
A micromechanical 13.1-MHz bulk acoustic mode silicon resonator having a high quality factor ( = 130000) and high maximum drive level ( = 0.12 mW at the hysteresis limit) is demonstrated. The prototype resonator is fabricated of single-crystal silicon by reactive ion etching of a silicon-on-insulator wafer. A demonstration oscillator based on the new(More)
A method for sintering nanoparticles by applying voltage is presented. This electrical sintering method is demonstrated using silver nanoparticle structures ink-jet-printed onto temperature-sensitive photopaper. The conductivity of the printed nanoparticle layer increases by more than five orders of magnitude during the sintering process, with the final(More)
Phase noise in capacitively coupled microresonator-based oscillators is investigated. A detailed analysis of noise mixing mechanisms in the resonator is presented, and the capacitive transduction is shown to be the dominant mechanism for low-frequency 1/f-noise mixing into the carrier sidebands. Thus, the capacitively coupled micromechanical resonators are(More)
Accurate total-energy pseudopotential methods are used to study the structures, binding energies, and local vibrational modes of various models for the Ga-O-Ga defect in GaAs. We find that the previously proposed models, OAs ~an off-centered substitutional oxygen in arsenic vacancy! and OI ~an oxygen atom occupying a tetrahedral interstitial site!, are(More)
Three electrostatic transduction methods are analyzed for a micromechanical, longitudinal mode, beam resonator. The conventional parallel plate transducer placed at the location of maximum displacement is compared to two solid, dielectric transducers internal to the resonator. Although the solid dielectric offers higher permittivity than the(More)
The geographical variation in the composition of triacylglycerols in seeds of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.], grown in Finland, was analyzed. The total lipid content of pine seeds was slightly higher in the northernmost provenance (68 °50′N), whereas the lipid content of spruce seeds was not affected(More)
This paper presents a passive wireless resonating sensor that is based on a ferroelectric varactor. The sensor replies with its data at an intermodulation frequency when a reader device illuminates it at 2 closely located frequencies. The paper derives a theoretical equation for the response of such a sensor, verifies the theory by simulations, and(More)
Contactless rapid electrical sintering (RES) is demonstrated using microwave power. The method is implemented by coupling the near-field electric field of a sintering head across an underlying nanoparticle layer. We provide appropriate biasing conditions required for controlled power delivery and demonstrate real-time monitoring of the process by measuring(More)
Performance of several time-of-flight (TOF) type ion mobility spectrometers (IMS) was compared in a joint measurement campaign and their mobility scales were adjusted based on the measurements. A standard reference compound 2,6-di-tert butylpyridine (2,6-DtBP) was used to create a single peak ion mobility distribution with a known mobility value. The(More)