Jarno Groenesteijn

Compact Mass Flow Meter Based on a Micro Coriolis Flow Sensor

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 connections and can be read out by means of a PC or laptop via USB. Its performance was tested for several common gases (hydrogen, helium, nitrogen, argon and air) and liquids (water and isopropanol). As in all Coriolis mass flow meters, the meter is also able to measure the actual density of the medium flowing through the tube. The sensitivity of the measured density is ~1 Hz.m3/kg.

Integrated multi-parameter flow measurement system

We have designed and realized an integrated multiparameter flow measurement system, consisting of an integrated Coriolis and thermal flow sensor, and a pressure sensor. The integrated system enables on-chip measurement, analysis and determination of flow and several physical properties of both gases and liquids. With the system, we demonstrated the feasibility to measure the flow rate, density, viscosity, specific heat capacity and thermal conductivity of hydrogen, helium, nitrogen, air, argon, water and IPA.

Single chip flow sensing system with a dynamic flow range of more than 4 decades

We have realized a micromachined single chip flow sensing system with an ultra-wide dynamic flow range of more than 4 decades, from less than 0.1 up to more than 1000 µl/h. The system comprises both a thermal and a micro Coriolis flow sensor with partially overlapping flow ranges.

Inline pressure sensing mechanisms enabling scalable range and sensitivity

We report on two novel capacitive pressure sensing mechanisms that allow measurements inline with other fluidic devices on one chip, without introducing a large internal volume to the fluid path. The first sensing mechanism is based on out-of-plane bending of a U-shaped channel and the same structure could be used for thermal flow sensing simultaneously. The second mechanism is based on deformation of the cross-section of the tube and allows for differential capacitive readout. The sensitivity and range of both mechanisms are scalable. The current implementations are tested up to 2.45 bar and 1 bar respectively.

An angular acceleration sensor inspired by the vestibular system with a fully circular fluid-channel and thermal read-out

We report on an angular accelerometer based on the semicircular channels of the vestibular system. The accelerometer consists of a water-filled circular tube, wherein the fluid flow velocity is measured thermally as a representation for the external angular acceleration. Measurements show a linear response for angular acceleration amplitudes up to 2×105° s-2.

Parametric excitation of a micro Coriolis mass flow sensor

We demonstrate that a micro Coriolis mass flow sensor can be excited in its torsional movement by applying parametric excitation. Using AC-bias voltages for periodic electrostatic spring softening, the flow-filled tube exhibits a steady vibration at suitable voltage settings. Measurements show that the sensor for this type of excitation can be used to measure water flow rates within a range of 0±500 ul/h with an accuracy of 1% full scale error.

Towards nanogram per second Coriolis mass flow sensing

We have designed, fabricated and tested a micromachined Coriolis flow sensor which can measure up to 50 μg s-1 at a maximum pressure drop of 1 bar with a zero stability of 14ng s-1 an improvement by a factor 40 compared to current state of the art Coriolis flow sensors. This resolution opens up new fields of applications which could up to now not be measured with Coriolis flow sensors.

Fully integrated microfluidic measurement system for real-time determination of gas and liquid mixtures composition

We have designed and realised a fully integrated microfluidic measurement system for real-time determination of both flow rate and composition of gas- and liquid mixtures. The system comprises relative permittivity sensors, pressure sensors, a Coriolis flow and density sensor, a thermal flow sensor and a thermal conductivity sensor. The composition of the mixture can be calculated from the physical properties - density, viscosity, heat capacity, thermal conductivity and relative permittivity - as measured by the integrated sensors in the system.

3D printed bio-inspired angular acceleration sensor

We present a biomimetic angular acceleration sensor inspired by the vestibular system, as found e.g. in mammals and fish. The sensor consist of a fluid filled circular channel. When exposed to angular accelerations the fluid flows relative to the channel. Read-out is based on electromagnetic flow sensing (pseudo Hall effect). The sensor is made out of two 3D printed parts which, when put together, form a channel and which allow for easy mounting of permanent magnets and electrodes to measure the flow induced potential difference. Experiments indeed show an acceleration dependent output voltage. However, we find strong contributions from other than electromagnetic sources which, due to their nature and magnitude, are interesting for further research.

Proportional Control Valves Integrated in Silicon Nitride Surface Channel Technology

We have designed and realized two types of proportional microcontrol valves in a silicon nitride surface channel technology process. This enables on-die integration of flow controllers with other surface channel devices, such as pressure sensors or thermal or Coriolis-based (mass) flow sensors, to obtain a proportional gas flow control system on a single chip. One valve design is implemented with inlet and outlet channels in the plane of the chip, which allows on-chip flow control between several fluidic components and allows up to 70 mgh-1 of flow at 200 mbar. The other valve design operates out-of-plane between surface channels and a fluidic inlet, offering a flow range up to 1250 mgh-1 at 600 mbar, smaller footprint, and low-leakage closure. Measured flow behavior agrees well with laminar flow models created for both valve types.