Silicone Rubber Input Element for Light-Touch Force Detection
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Solution Overview
Problem
Existing input elements, such as those using polyvinylidene fluoride (PVDF), require significant force for operation, leading to inconvenient and non-intuitive input experiences, especially when attempting to perform light-touch operations like finger gestures, often necessitating a twice-pressing operation.
Innovation Solution
An input element comprising a first and second electrode with an intermediate layer made of silicone rubber or a rubber composition, where the intermediate layer undergoes surface modification and deactivation treatments to enhance its deformation properties and generate a large electric signal, allowing for reliable light operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PVDF base material is used to detect pressing force through piezoelectric effect, then detection capability is achieved, but sufficiently large pressing force is required making light operability unavailable
Solution Approach 1:
The patent changes the material parameter from PVDF (piezoelectric effect requiring large force) to silicone rubber or rubber composition (elasticity-based deformation). This parameter change enables the intermediate layer to deform easily under light touch while still generating detectable electrical signals between conductive layers, resolving the contradiction between detection capability and ease of operation.
Solution Approach 2:
The patent employs a composite structure consisting of silicone rubber or rubber composition as the intermediate layer between conductive layers. This composite material approach allows the layer to exhibit both sufficient elasticity for light operability and adequate electrical properties for pressing force detection, simultaneously achieving measurement precision and ease of operation.
2Reliability
If PVDF material is used for input element, then voltage generation through piezoelectric effect is achieved, but twice-pressing operation is often necessary causing inconvenience
Solution Approach 1:
The patent changes the physical parameter of the intermediate layer from rigid PVDF to flexible silicone rubber or rubber composition. This enables single-press operation with light touch while maintaining reliable input detection, eliminating the need for twice-pressing operations and improving operational convenience without sacrificing reliability.
3Ease of operation
If intermediate layer is made of rubber or rubber composition containing siloxane, then large electric signal is generated enabling light operability, but surface modification and deactivation treatments are required
Solution Approach 1:
The patent changes the surface property parameter of the rubber intermediate layer through modification and deactivation treatments. These treatments adjust the surface characteristics to optimize electrical signal generation while controlling adhesion properties, enabling light operability with single-press operation. Although additional processing steps are involved, they are standard industrial treatments that ensure consistent performance.
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 input element achieves reliable and sensitive detection of pressing forces with reduced operational force requirements, enabling comfortable and intuitive input operations, such as single-touch gestures, without the need for signal amplification.
Implementation Method 1
detects a position and a pressing force by detecting current generated from a position to which a force is applied
Data Source
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AI summary
An input element includes: a first electrode and a second electrode that face each other; and an intermediate layer disposed between the first and the second electrodes and made of rubber or a rubber composition, the rubber or rubber composition containing siloxane. The intermediate layer is made of rubber or a rubber composition, the rubber or rubber composition containing siloxane that has a silicon atom bound to three to four oxygen atoms. The intermediate layer has concentration profiles such that, while oxygen increases from one side to the other side of a thickness direction thereof and has a maximal value, carbon decreases from the one side to the other side thereof and has a minimal value.