Joost C. Lötters

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This paper presents a new inherently triaxial accelerometer-based system for determining the ability to maintain balance while standing. In this study, the accelerometer was placed at the back of the subject at the approximate height of the centre of mass. The data were processed to obtain five performance parameters. Paired t-tests indicated that the(More)
Polydimethylsiloxane (PDMS) is a commercially available physically and chemically stable silicone rubber. It has a unique flexibility with a shear elastic modulus G ≈ 250 kPa due to one of the lowest glass transition temperatures of any polymer (Tg ≈ −125 ◦C). Further properties of PDMS are a low change in the shear elastic modulus versus temperature (1.1(More)
There is a need for capacitance to voltage converters (CVC’s) for differential capacitive sensors like pressure sensors and accelerometers which can measure both statically and dynamically. A suitable CVC is described in this paper. The CVC proposed is based on a symmetrical structure containing two half ac bridges, is intrinsically immune to parasitic(More)
Polydimethylsiloxane is a silicone rubber. It has a unique flexibility, resulting in one of the lowest glass-transition temperatures of any polymer. Furthermore, it shows a low elasticity change versus temperature, a high thermal stability, chemical inertness, dielectric stability, shear stability and high compressibility. Because of its high flexibility(More)
In this paper the quantitative influence of external vibrations on the measurement value of a Coriolis Mass-Flow Meter for low flows is investigated, with the eventual goal to reduce the influence of vibrations. Model results are compared with experimental results to improve the knowledge on how external vibrations affect the measurement error. A Coriolis(More)
Precise mass flow control is an essential requirement for novel, small-scale fluidic systems. However, a small-volume, low-leakage proportional control valve for minute fluid flows has not yet been designed or manufactured. A survey is therefore made of the primary design considerations of a micromachined, proportional control valve. Performance(More)
In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1 mg/h/°C. The meter is robust, has standard fluidic(More)
Problems occur regularly with intravenous therapy, especially with the flow behavior. A mechanical model can predict which components of intravenous therapy systems introduce non-ideal effects in the flow. This study concentrates on gaining quantitative information of each separate component for intravenous therapy, characterize its non-ideal effects and(More)
In this paper we describe the development of a system and model to analyze the composition of gas mixtures up to four components. The system consists of a Coriolis mass flow sensor, density, pressure and thermal flow sensor. With this system it is possible to measure the viscosity, density, heat capacity and flow rate of the medium. In a next step the(More)
We have designed and realised a micromachined micro Coriolis flow sensor for the measurement of hydrazine (N2H4, High Purity Grade) propellant flow in micro chemical propulsion systems. The sensor should be able to measure mass flow up to 6 mg/s for a single thruster or up to 24 mg/s for four thrusters. The sensor will first be used for measurement and(More)