DESIGN, IMPLEMENTATION AND CHARACTERIZATION OF CONSTANT TEMPERATURE ANEMOMETRY CIRCUITS FOR MEMS WALL SHEAR STRESS SENSOR

Before the introduction of MEMS thermal wall shear stress sensor, the precise and accurate measurement of the flow remained a difficult task but thanks to its simple functionality and minimum flow disruption during the operation the difficulty of this task has been significantly been reduced. The ME

Project Title

DESIGN, IMPLEMENTATION AND CHARACTERIZATION OF CONSTANT TEMPERATURE ANEMOMETRY CIRCUITS FOR MEMS WALL SHEAR STRESS SENSOR

Project Area of Specialization

Wearables and Implantable

Project Summary

Before the introduction of MEMS thermal wall shear stress sensor, the precise and accurate measurement of the flow remained a difficult task but thanks to its simple functionality and minimum flow disruption during the operation the difficulty of this task has been significantly been reduced. The MEMS thermal wall shear stress sensor chip contains four types of hot-wire made up of different material these are HVM25A, HVM25B, HVM25C and HVM25D each sensor also contains different length of hot-wire element 50um, 100um, 150um, 200um and 400um. Each length has the same diameter except for the 400um.

 The HVM25A and HVM25B are already been characterized and calibrated. Our aim is to characterize the HVM25C and HVM25D of each length and then design and fabricate the corresponding anemometry circuitry according to the cold and hot resistances and the temperature rise. Constant Current Anemometry, Constant Voltage Anemometry and Constant temperature Anemometry are types of Hot wire anemometry circuits. We will design the all three of these.

Project Objectives

• Characterization of MEMS Wall Shear Stress Sensor HV-25.
• Designing of Anemometry Circuits.
• Calibration with Wind Tunnel

Project Implementation Method

First, we  bond  our sensor HVM 25C and HVM 25D chips which is necessary for the characterizations of the sensors.

The characterizations of sensors consist of finding the cold resistance, TCR (temperature coefficient of resistance), developing the IV and power VS temperature curves for each sensor. Then the designing we consists of the design of our three anemometry circuits i.e. CCA, CTA and CVA according to the cold resistances and the maximum current each sensor can take. Finally, the fabrication consist of using these anemometry circuits on MEMS lab wind tunnel to develop the shear stress sensitivity graph for each sensor. Then we use a microcontroller which will allow the user to select any sensor he wants and also the anemometry circuit we wants for this sensor, then by using the values the microcontroller we display the voltage, current, power, temperature, resistance and wall shear stress on the liquid crystal display (LCD).

Benefits of the Project

first time in pakistan,

•HVM-25C and HVM-25D were characterized.

•Corresponding anemometry circuits were designed in three different modes i.e. CCA, CTA and CVA.

•Calibration with wind tunnel was done to develop shear stress vs velocity and shear stress vs current graph.

Technical Details of Final Deliverable

Finding the Characteristics of HVM-25C and HVM-25D.

oBonding of Sensor Chips

oCold Resistance measurement

oI-V Characteristics

oTemperature Coefficient of Resistance (TCR)

oPower vs Temperature Behaviour

oShear Stress Vs Voltage (CCA & CTA)

oShear Stress Vs Current (CVA)

Designing Anemometry Circuits.

oConstant Temperature Anemometer (CTA), Constant Current Anemometer (CCA), Constant Voltage Anemometer (CVA).

oDesign to match cold resistance and hot resistance.

Fabrication

oManufacturing of PCB for CTA, CCA and CVA circuits.

oCalibration of wind tunnel with anemometry circuits.

Final Deliverable of the Project

HW/SW integrated system

Type of Industry

Education , Manufacturing , Others

Technologies

Artificial Intelligence(AI), Robotics, Wearables and Implantables, Others

Sustainable Development Goals

Quality Education, Industry, Innovation and Infrastructure, Partnerships to achieve the Goal

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com