Pressure Sensor with Cylindrical Cavity and Silicone Oil for Grasping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diaphragm-type ultrasonic sensor devices face issues with the breakage of piezoelectric bodies or membranes due to direct contact with objects, leading to local force application and potential damage when used in grasping applications.
Innovation Solution
A pressure sensor design featuring a supporting body with a cylindrical cavity and a sealing film, where a pressure medium is filled to disperse forces, preventing direct contact between the object and the piezoelectric body, and a flexible frame body that contracts to detect pressure, along with a sensor array configuration that includes both pressure and ultrasonic sensors for enhanced reliability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the piezoelectric body is exposed to the outside for direct object contact, then pressure detection capability is improved, but the piezoelectric body becomes vulnerable to local force application and breakage
Solution Approach 1:
A pressure medium (gas or liquid) is introduced as an intermediary between the object and the piezoelectric body. The pressure medium transmits pressure forces to the piezoelectric body while dispersing localized forces, preventing direct contact and reducing the risk of breakage while maintaining pressure detection capability
Solution Approach 2:
The pressure medium acts as a cushioning layer that absorbs and disperses impact forces before they reach the piezoelectric body. This protective mechanism prevents sudden localized forces from causing damage to the fragile piezoelectric components
2Reliability
If a rigid protective structure is added around the piezoelectric body, then protection against breakage is improved, but flexibility and pressure detection accuracy deteriorate
Solution Approach 1:
A flexible frame body with a cylindrical cavity is used instead of rigid protective structures. The flexible membrane allows the piezoelectric body to be protected while maintaining the ability to transmit pressure forces accurately, as the flexible structure can deform slightly to accommodate pressure changes without compromising the piezoelectric body
3Measurement precision
If the piezoelectric body is directly exposed for pressure detection, then pressure sensing is improved, but the membrane becomes susceptible to local force concentration and damage
Solution Approach 1:
The pressure medium serves as a mediator that distributes localized forces across a larger area of the membrane and piezoelectric body. By transmitting pressure through the fluid medium, the force is dispersed rather than concentrated at single points, protecting the membrane from damage while maintaining pressure sensing capability
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 effectively prevents breakage of the pressure detecting portion and membrane, allows for accurate pressure detection, and enhances the reliability of the sensor array by dispersing forces and using a flexible frame body, while also enabling simultaneous object recognition and pressure detection.
Implementation Method 1
a pressure medium which disperses a force is filled in the inner space of the frame body
Implementation Method 2
a piezoelectric body provided on the diaphragm portion and deflecting to output an electric signal
Implementation Method 3
a flexible frame body that contracts to detect pressure
Data Source
AI summary
A pressure sensor includes: a supporting body which has an opening; a pressure detecting portion which includes a supporting film provided on the supporting body and having a diaphragm portion closing the opening, and a piezoelectric body provided on the diaphragm portion and deflecting to output an electric signal; a frame body which has, on the pressure detecting portion, a cylindrical cavity along a film thickness direction of the supporting film, and is formed, in plan view when viewed from the film thickness direction of the supporting film, at a position where a cylindrical inner peripheral wall of the cavity overlaps with the opening, or outside of the opening; a sealing film which closes the frame body; and a silicone oil which is filled in an inner space formed of the cylindrical inner peripheral wall of the cavity, the sealing film, and the pressure detecting portion.