Through-Enclosure Pressure Sensing for Compact Wearable Force Input
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional force sensors are bulky, expensive, and lack precision, making them unsuitable for small form factor applications, low-cost durable devices, and high-precision applications, such as wearable electronics and medical devices, due to structural limitations and nonlinear sensitivity.
Innovation Solution
An interface pressure sensor system utilizing a microelectromechanical fluid pressure sensor encapsulated within a rigid module enclosure with an infill material, which redirects shear forces and enhances sensitivity by concentrating pressure input along a normal axis, allowing for precise pressure measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional force sensors are used, then force sensing capability is achieved, but device volume and area are substantially increased
Solution Approach 1:
The patent combines the force sensing function with the existing barometric pressure sensor and encapsulation materials. The encapsulation material serves dual purposes: protecting the pressure sensor and transmitting force to it. The rigid module enclosure simultaneously provides structural support and directs shear forces to the pressure sensor diaphragm, eliminating the need for separate force sensor components.
Solution Approach 2:
The pressure sensor diaphragm is designed to perform multiple functions: sensing ambient pressure changes (barometric function) and transmitting applied force for force sensing. The encapsulation material also serves multiple roles: mechanical protection, force transmission, and environmental sealing. This multi-functionality reduces overall device volume while maintaining both pressure and force sensing capabilities.
2Force
If conventional force sensors are used, then force sensing is achieved, but manufacturing cost increases
Solution Approach 1:
The patent makes the pressure sensor and encapsulation materials serve dual functions - both pressure sensing and force sensing. This eliminates the need for separate force sensor components, reducing part count and manufacturing complexity. The same diaphragm and encapsulation structure used for pressure sensing are leveraged for force sensing, achieving cost-effective multi-functionality.
Solution Approach 2:
The encapsulation material and rigid module enclosure automatically perform force direction and transmission functions through their structural design. The rigid enclosure's geometry naturally directs shear forces normal to the diaphragm surface without requiring additional mechanical components. This self-service approach reduces assembly complexity and manufacturing costs.
3Force
If conventional force sensors are used, then force sensing is achieved, but measurement precision and accuracy deteriorate due to structural limitations
Solution Approach 1:
The encapsulation material acts as an intermediary that efficiently transmits applied force to the pressure sensor diaphragm. The rigid module enclosure serves as another intermediary that directs shear forces normal to the diaphragm surface. These intermediaries ensure that force is transmitted uniformly and accurately to the sensing element, improving measurement precision by eliminating structural limitations of conventional force sensors.
4Volume of moving object
If small form factor is achieved, then device size is reduced, but force sensing precision deteriorates
Solution Approach 1:
The patent merges force sensing and pressure sensing functions into a single integrated sensor module. The pressure sensor diaphragm and encapsulation structure serve both sensing modalities, eliminating the need for separate force sensor components that would increase device volume. This integration maintains small form factor while achieving adequate force sensing precision through the efficient force transmission path.
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 system enables accurate and precise measurement of pressure and force inputs in a compact form factor, suitable for various applications including biometric sensing and user input, while being cost-effective and durable.
Implementation Method 1
a microelectromechanical force or pressure sensitive structure that deforms in response
Implementation Method 2
the encapsulation material transits that force, or at least a portion thereof, to a microelectromechanical force or pressure sensitive structure that deforms in response
Data Source
AI summary
An interface pressure sensor includes a fluid pressure sensor disposed in a volume defined by a shear wall. The volume is enclosed, and the fluid pressure sensor is encapsulated by, an infill material. The infill material defines a sensing surface that, when pressed, can impart a force that is detectable by the fluid pressure sensor.