Johannes Enlund

Surface acoustic wave-induced precise particle manipulation in a trapezoidal glass microfluidic channel

Surface acoustic wave (SAW) excitation of an acoustic field in a trapezoidal glass microfluidic channel for particle manipulation in continuous flow has been demonstrated. A unidirectional interdig ...

A micromachined Stoneley acoustic wave system for continuous flow particle manipulation in microfluidic channels

Particle manipulation utilizing interface acoustic waves (IAWs) is proposed for the first time. An IAW-based manipulation system has been designed, micromachined and tested. This work addresses the issue of particle manipulation in microfluidic channels with particular emphasis on particles with submicron dimensions. The subject is of significant relevance for a range of bio-technological applications and in particular for lab-on-chip ones. Submicron particle manipulation in continuous flow has been demonstrated.

Oscillators Based on Monolithically Integrated AlN TFBARs

Oscillators based on AlN thin-film bulk acoustic resonators are designed, fabricated and measured. The circuits are realised as silicon-on-silicon multichip modules where SiGe transistors are flip-chip mounted on a novel carrier substrate which includes monolithically integrated resonators and passive components. The paper describes the development and processing of the carrier substrate and resonators, as well as the development of the oscillator circuits.

Optimisation of a smooth multilayer nickel silicide surface for ALN growth

For use in thin film electroacoustic (TEA) technology a few hundred nanometre thick nickel silicide (NiSi) electrode would need to be fabricated. A complete fabrication process for the formation of over 200 nm thick silicide films has been optimised for use as an electroacoustic electrode. Optimisation of silicidation temperature and identification of the mono phase of silicide is demonstrated. Thick electrodes are formed by depositing multilayers of silicon and nickel pairs onto silicon (Si) substrates before rapid thermal annealing. The numbers of multilayers and relative material thicknesses are optimized for both surface roughness and electrical resistivity. The growth of textured aluminium nitride (AlN) has been investigated on the optimised surfaces.

A 2 GHz oscillator based on a solidly mounted thin film bulk acoustic wave resonator

This paper describes the design and measurement of a 2 GHz oscillator based on a solidly mounted thin film bulk acoustic wave resonator (SM TFBAR). The circuitry is patterned on an alumina substrate on which the transistors and capacitors are soldered. The SM TFBAR chip is integrated by means of wirebonding. The measured oscillator centre frequency is about 2.038 GHz with an output power of 0 dBm

FBAR Sensor Array for in Liquid Operation

This letter discusses the design of thickness shear mode thin-film bulk acoustic resonator (FBAR) sensor array for in liquid operation with respect to minimizing the observed Q-degradation and crosstalk.

A 2 GHz oscillator using a monolithically integrated AlN TFBAR

A 2 GHz oscillator based on a solidly mounted AlN Thin-Film Bulk Acoustic Resonator (TFBAR) is reported. The oscillator is realised as a silicon-on-silicon Multi-Chip Module (MCM) where all passive elements, including the TFBAR, are monolithically integrated on a High-Resistivity Silicon (HRS) carrier. SiGe transistors are flipchip mounted on the MCM carrier. Measurements of the oscillators reveal a best phase-noise of −125 dBc/Hz at 100 kHz offset.

4E-6 Electric Field Sensitivity of Thin Film Resonators Based on Piezoelectric AlN Thin Films

Thin film bulk acoustic wave resonators (FBAR), solidly mounted resonators (SMR), and thin film plate acoustic resonators (FPAR) based on piezoelectric aluminum nitride (AlN) are all attractive candidates for monolithically integrated filters, sensors and oscillators operating in the gigahertz frequency range. This work aims at performing a systematic study of the DC electric field sensitivity of FBAR, SMR and FPAR devices fabricated with the same technology and utilizing membranes with comparable thicknesses. Further, the results are presented in terms of the electric field coefficient of frequency (ECF) which is supposed to be a thickness independent value under certain assumptions. The ECF coefficients of the devices under study were extracted from the frequency shift in the recorded frequency spectra. No hysteresis effects are observed during the measurements. Finally, a novel frequency tuning concept for FPARs based on biasing the distributed reflectors, thus shifting the frequency stopband edges, is reported. The effects studied can be utilized for active temperature compensation circuits as well as for static voltage sensors

Interface acoustic wave based manipulation of sub-micrometer particles in microfluidic channels

The work in question addresses the issue of continuous flow particle manipulation in liquid media with particular emphasis on particles with micron and sub-micron dimensions. The subject is of significant relevance for a range of bio-technological applications and in particular for lab-on-chip ones. Particle manipulation utilizing Interface Acoustic Waves (IAW) is proposed for the first time. Manipulation of submicron sized particles is successfully demonstrated in a streaming free regime.