High-performance piezoresistive MEMS strain sensor with low thermal sensitivity

Area of Science:

• Materials Science and Engineering
• Mechanical Engineering
• Electrical Engineering

Background:

• Piezoresistive microelectromechanical systems (MEMS) sensors are crucial for strain measurement.
• Existing MEMS strain sensors face limitations in sensitivity and signal loss.
• Geometric optimization of the sensor's silicon carrier offers a potential solution.

Purpose of the Study:

• To experimentally evaluate a new piezoresistive MEMS strain sensor with enhanced sensitivity.
• To validate the effectiveness of introduced surface features (trenches) for stress concentration.
• To compare experimental results with Finite Element Analysis (FEA) simulations for optimization.

Main Methods:

• Fabrication of MEMS sensors using five different doping concentrations.
• Experimental testing across a temperature range of -50 °C to +50 °C.
• Finite Element Analysis (FEA) to investigate bonding adhesive properties, layer thickness, and rotational errors.

Main Results:

• Introduced surface features successfully created stress concentration regions, improving sensor sensitivity.
• Experimental data correlated well with FEA simulations, validating the design methodology.
• Analysis provided guidance for selecting bonding adhesives and installation procedures.

Conclusions:

• Geometric modification of the silicon carrier is an effective strategy to enhance piezoresistive MEMS strain sensor sensitivity.
• The study confirms the feasibility of using stress concentration regions to improve sensor performance.
• FEA is a valuable tool for optimizing MEMS sensor design, material selection, and installation.