cMUT Array Boundary Cell Inactivation for Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The nonuniformity of capacitive micromachined ultrasonic transducer (cMUT) cells due to boundary conditions in two-dimensional arrays leads to operational reliability and acoustic characteristic issues, particularly affecting cells at the edges and corners of the transducer array.
Innovation Solution
The implementation of a two-group cell arrangement where only uniformly manufactured cells in the first group are active, and the second group, located at the periphery, is either filled with a material to prevent displacement or lacks electrodes to inhibit signal transmission and reception, thereby reducing nonuniformity and ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If cells are arranged in a two-dimensional array to increase transducer coverage area, then the transducer can cover a broader area, but cells at the boundary portions exhibit nonuniform structure and reduced operation reliability
Solution Approach 1:
The patent divides the cMUT array into two distinct segments: active cells in the central region and inactive dummy cells at the boundary portions. This segmentation allows the boundary cells to be structurally complete but electrically inactive, eliminating their negative impact on transducer performance while maintaining the benefits of a large two-dimensional array coverage area.
Solution Approach 2:
The patent extracts or removes the harmful function of boundary cells by making them inactive through various methods (filling with resin, removing electrodes, or making membranes non-vibrating). This extraction eliminates the nonuniformity and reliability issues associated with boundary cells while preserving the overall array structure and coverage area.
2Productivity
If all cells in the array are made active to maximize transducer functionality, then signal transmission and reception capacity increases, but nonuniformity among cells degrades overall performance
Solution Approach 1:
The patent applies different functional qualities to different regions of the array: central cells are designed with complete electrodes and vibrating membranes for active signal transmission and reception, while boundary cells are designed with modified structures (filled spaces, removed electrodes, or constrained membranes) that render them inactive. This local differentiation ensures high uniformity among active cells while maintaining overall array integrity.
3Device complexity
If boundary cells are included in the active array to utilize full manufactured structure, then device complexity is reduced, but acoustic characteristics and transmission-reception sensitivity are degraded
Solution Approach 1:
The patent performs preliminary action by designing and manufacturing complete cell structures at the boundary portions, then subsequently deactivating them through filling, electrode removal, or mechanical constraint. This approach allows the use of standard manufacturing processes for all cells while ensuring that boundary cells do not degrade acoustic characteristics or sensitivity before the transducer is put into service.
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
This approach enhances the uniformity and stability of cMUT cell operation, improving transmission-reception sensitivity and overall reliability of the ultrasonic transducer when used in ultrasonic imaging applications.
Implementation Method 1
The cMUT functions as an electro-acoustic transducer by applying voltage to electrodes provided in the vibrating membrane and in the lower side substrate
Implementation Method 2
capacitive micromachined ultrasonic transducers (cMUT) have been studied a lot recently
Data Source
AI summary
The invention aims to give uniform and stable characteristics to a cMUT-cell array and to improve acoustic characteristics. To this end, a signal blocking section is additionally provided for cells 102 located in the outermost peripheral portion or at the end positions of a two-dimensional array 101 of cMUT cells that are designed and manufactured as ones usable as an ordinary transducer capable of transmission and reception of signals. The signal blocking section is provided to prevent the displacement and the vibration of the cells, and to block the transmission and the reception of signals.