Capacitive Touch Device on Non-Flat Surfaces

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Solution Overview

Problem

Capacitive touch devices are challenging to integrate into non-flat surfaces, such as curved or sculpted objects, as existing methods often result in electrical isolation of conductive regions, damage to the substrate, and limitations in surface finish and durability.

Innovation Solution

A capacitive touch system is implemented using a flexible substrate with capacitive touch elements formed on a flat surface, which is then cut and folded into a three-dimensional shape, with overlapping strips ensuring capacitive coupling across the substrate, and a housing made of durable plastic to accommodate the shape, while using conductive ink and a microcontroller for interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If capacitive touch devices are formed on flat surfaces and then shaped into three-dimensional forms, then the device can be integrated into non-flat articles, but conductive regions may become electrically isolated

Engineering Contradiction:
Improveadaptability to non-flat surfacesVSAvoidelectrical connectivity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The substrate is divided into multiple strips that are separated by cutting, allowing each strip to be independently positioned and overlapped with adjacent strips to maintain electrical connectivity while forming a three-dimensional shape

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple strips of the substrate are overlapped and nested together, with each strip containing portions of conductive elements that overlap with adjacent strips, ensuring continuous electrical pathways through the three-dimensional structure

Inventive Principle:
Principle #7Nested doll (Nesting)

2Shape

If the substrate is cut and folded to form a three-dimensional shape, then the device can accommodate curved surfaces, but the cut lines may need to be carefully positioned and the substrate may be damaged

Engineering Contradiction:
Improvethree-dimensional configurationVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The substrate is segmented into multiple strips through cutting, which simplifies the manufacturing process by allowing standard cutting patterns to be used while still achieving the desired three-dimensional configuration when the strips are overlapped and assembled

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flexible substrate allows for cutting and folding into three-dimensional shapes without damage, as the material can be manipulated into curved and angular configurations while maintaining structural integrity

Inventive Principle:
Principle #30Flexible shells and thin films

3Adaptability or versatility

If the substrate forms the body of the article, then the article can be formed with the touch device integrated, but the substrate may be damaged and limit surface finish options

Engineering Contradiction:
Improveintegration with article structureVSAvoidsubstrate durability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The substrate is divided into multiple strips that are overlapped and secured within a housing, distributing mechanical stresses across multiple segments rather than concentrating them in a single continuous substrate, thereby improving durability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flexible substrate can be manipulated into three-dimensional configurations and secured within a housing structure, allowing the substrate to conform to the article shape without being the primary structural component, thus protecting it from damage

Inventive Principle:
Principle #30Flexible shells and thin films

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

Enables interactive and responsive touch input on non-flat surfaces without electrical isolation and maintains a durable, aesthetically pleasing appearance, allowing for applications like an interactive globe or toy.

Implementation Method 1

overlapping strips ensuring capacitive coupling across the substrate

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3210099B1Article comprising a capacitive touch device
Publication Date: 2022.11.23 NOVALIA
  • EP3210099B1 patent drawingFigure 1~2
  • EP3210099B1 patent drawingFigure 3~5
  • EP3210099B1 patent drawingFigure 6

AI summary

An article (1), such as globe, comprises a housing portion or substrate (3), which may be non-flat, and a capacitive touch device (6), such as an x-y touch pad. The capacitive touch device comprises a first capacitive touch device part which comprises a first substrate (12) supporting a first conductive track or pad (14) and a second capacitive touch device part which comprises a second substrate (13) supporting a second conductive track or pad (15). The first and second capacitive touch device parts overlap so as to capacitively couple the first conductive track or pad and the second conductive track or pad. The capacitive touch device (6) is disposed adjacent to the housing portion (3).