MEMS Pressure Transducer with Polymer Bubble Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pressure transducers are too large for applications such as intracranial, cardiac, and intraocular pressure monitoring, and industrial sensing, requiring a smaller footprint with the ability to measure hydrostatic pressure effectively.
Innovation Solution
A microelectromechanical systems (MEMS) pressure transducer with a chamber less than 1 mm in size, utilizing a polymeric material like Parylene-C, and an electrochemical impedance sensing mechanism that generates and measures changes in a gaseous bubble within a fluid to detect pressure changes, eliminating the need for a diaphragm and allowing for wireless operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional pressure transducers are used, then pressure measurement function is achieved, but device footprint is too large (300-400 μm)
Solution Approach 1:
The pressure transducer is segmented into distinct functional components: a pressure-sensitive membrane, a sealed chamber, and electronic sensing elements. This segmentation allows each component to be optimized independently, enabling the overall device to achieve a reduced footprint of less than 300 μm while maintaining pressure measurement functionality through the coordinated operation of these specialized sub-components.
Solution Approach 2:
The patent transitions from planar two-dimensional pressure sensing to three-dimensional volumetric sensing by incorporating a sealed chamber that responds to pressure changes in multiple dimensions. This dimensional expansion allows the sensor to detect pressure through volume changes of the chamber, enabling accurate measurement within a compact footprint by utilizing the third dimension (depth/volume) rather than relying solely on surface area.
2Reliability
If hermetic packaging is used for conventional transducers, then environmental protection is achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the protective packaging function directly into the sensor chamber structure itself. The sealed chamber is integrated as an intrinsic part of the pressure sensing element, eliminating the need for separate hermetic packaging layers. This integration maintains environmental protection and reliability by sealing the pressure-sensitive components while significantly reducing device complexity and manufacturing steps.
Solution Approach 2:
The chamber structure serves dual functions: it is both the pressure sensing element and the protective seal. The chamber walls themselves provide the hermetic barrier against environmental contaminants, eliminating the need for additional protective packaging layers. This self-service approach reduces device complexity while maintaining reliability through the multifunctional chamber design.
3Adaptability or versatility
If larger transducers are used, then manufacturing is easier, but application versatility in biomedical and industrial fields is limited
Solution Approach 1:
The patent employs parameter changes in the chamber dimensions, material properties, and sensing element geometry to optimize the transducer for specific applications. By adjusting these parameters, the same basic design can be adapted for different pressure ranges, fluid types, and application requirements (biomedical, industrial, environmental), thereby achieving high versatility without complicating the fundamental manufacturing process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a compact, low-power pressure transducer with a reduced sensor footprint, capable of accurate hydrostatic pressure measurement in various applications, including biomedical and industrial settings, without the need for hermetic packaging, and with the ability to function wirelessly.
Implementation Method 1
measure hydrostatic pressure within the chamber
Implementation Method 2
electrodes configured to generate the gaseous bubble by electrolysis
Implementation Method 3
electrochemical impedance sensing components configured to measure changes in the impedance of the fluid caused by changes in the volume of the gaseous bubble
Data Source
AI summary
A pressure transducer for measuring pressure may include an all-polymer chamber that has no dimension greater than 1 mm. There may be fluid within the chamber, a gaseous bubble trapped within the fluid, and electrodes in contact with the fluid. The electrodes may enable a measurement of changes in the impedance of the fluid caused by changes in the volume of the gaseous bubble caused by changes in the pressure to be measured.The pressure transducer may be made by depositing the chamber, placing the fluid within the chamber, and generating the gaseous bubble within the fluid with electrolysis.