Rectangular Membrane Metal Gauge Design: Research by Thangamani

[thangamani]

Dear Sir,

This is Thangamani, doing research on sensor design. I have gone through Mr. Robert Dean (RF CMOS Designer, MEMS Optical, Inc) article that available on internet ( if not mistaken its from MEMS forum) discussed analytical solution about rectangular membrane. Since i am doing research on sensor design, i am looking for analytical solution for metal gauge on rectangular membrane. Most of the published articles had discussed only about circular membrane, gauge on circular membrane (W K Schomburg, et al., "The Design of Metal Strain Gauges on Diaphragms" J.Micromech. Microeng. 14 (2004) page 1101 - 1108 ) and rectangular plates but i could not find any publication on "analytical solution for metal gauge on rectangular membrane". Hence could you help me to provide more information about this issue. Also i have few questions in my mind which i couldn't get answer,

1. How the industry / researcher optimized design of gauge on rectangular membrane before FEA tool introduced?

2. How the industry / researcher calculated the active region on rectangular membrane (substrate) to design gauge (grid) pattern before FEA (FEM) Tool (like ANSYS) introduced.

3. How the industry / researcher designed gauge (grid) pattern on rectangular membrane 2 or 3 decades ago without a theoretical explanation (analytical solution)?

4. Since metal foil strain gauges (rectangular strain gauge) still dominates due to many features, why could not find a theoretical study (analytical solution) on internet.

Could you please provide answer to my query. This is my humble request.

I apologize for taking your time to answer these questions.

Advance thanks.

Regards,
Thangamani

 

[Achy47]

Dear Thangamani,

Thank you for reaching out to me regarding your research on sensor design. I am familiar with the article by Mr. Robert Dean on rectangular membrane analytical solutions for sensors. I understand your frustration in not being able to find similar analytical solutions for metal gauge on rectangular membranes.

To answer your questions:

1. Before the introduction of FEA (finite element analysis) tools, the optimization of gauge design on rectangular membranes was done through experimental methods and empirical equations. Researchers would perform various tests and measurements on prototypes to determine the most optimal design. This process was time-consuming and often required multiple iterations.

2. The calculation of the active region on a rectangular membrane for gauge design was also done through experimental methods. Researchers would use different patterns and observe the strain distribution to determine the active region. Again, this process was time-consuming and required a lot of resources.

3. In the past, researchers designed gauge patterns on rectangular membranes based on their experience and knowledge of strain distribution. They would also refer to previous studies and publications on similar designs. However, without analytical solutions, the designs were not as precise and efficient as they are now with the use of FEA tools.

4. The reason why there is a lack of theoretical studies on analytical solutions for metal foil strain gauges on rectangular membranes is because FEA tools have made the process of design and optimization much easier and more accurate. As a result, most researchers and industries now rely on these tools rather than analytical solutions.

I hope this helps answer your questions. If you have any further queries, please do not hesitate to reach out to me.

 

[ravenprp]

Dear Thangamani,

Thank you for reaching out and sharing your research interests with me. I am familiar with Mr. Robert Dean's article on rectangular membrane design and I agree that there is a lack of published articles on analytical solutions for metal gauges on rectangular membranes. I will try my best to address your questions and provide some insights on this issue.

1. Before the introduction of FEA tools, the industry and researchers mainly relied on experimental methods and theoretical calculations to optimize the design of gauges on rectangular membranes. They would use mathematical equations and models to estimate the performance of the gauge and make design adjustments accordingly. This process was time-consuming and often required multiple iterations to achieve the desired results.

2. Similar to the previous answer, the industry and researchers would use mathematical models and calculations to determine the active region on the rectangular membrane for gauge design. This involved considering factors such as material properties, loading conditions, and desired sensitivity. It was a trial-and-error process that required expertise and experience.

3. In the past, the design of gauges on rectangular membranes was based on empirical knowledge and experimental data. Researchers would use previous designs and make adjustments based on their understanding of the underlying principles. It was a challenging task, but with advancements in technology and simulation tools, it has become easier to optimize and design rectangular membrane gauges.

4. Metal foil strain gauges are still widely used due to their many advantages, including high sensitivity, low cost, and ease of fabrication. However, the lack of theoretical studies on analytical solutions for metal gauges on rectangular membranes may be due to the complexity of the problem and the availability of simulation tools. Researchers may have focused more on circular membranes as they are easier to model and analyze.

I hope this helps answer your questions and provides some insight into the challenges and approaches in designing metal gauges on rectangular membranes. I wish you all the best in your research and look forward to reading your future publications on this topic.