Microsoft Patent | Forming Touch Sensor on Fabric

Patent: Forming Touch Sensor on Fabric

Publication Number: 20190025953

Publication Date: 2019-01-24

Applicants: Microsoft

Abstract

Examples are disclosed that relate to touch sensors formed on fabrics. One example provides a touch sensor including a fabric layer, a first electrode having a conductive ink disposed on the fabric layer, a dielectric structure disposed over the first electrode, the dielectric structure including an electrode support layer and an adhesive layer bonding the electrode support layer to the fabric layer and the first electrode, and the touch sensor also including a second electrode disposed on the electrode support layer.

Background

Touch sensors may be configured to detect touch via a variety of methods, including but not limited to capacitive methods. Touch sensors are commonly used as user input mechanisms for computing devices.

Summary

Examples are disclosed that relate to touch sensors formed on fabrics. One example provides a touch sensor including a fabric layer, a first electrode having a conductive ink disposed on the fabric layer, a dielectric structure disposed over the first electrode, the dielectric structure including an electrode support layer and an adhesive layer bonding the electrode support layer to the fabric layer and the first electrode, and the touch sensor also including a second electrode disposed on the electrode support layer.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

Touch sensors generally take the form of a sensing array integrated into a rigid surface, which may or may not be transparent, depending upon the implementation. However, rigid touch sensors may not be suitable for incorporating into soft-touch items, such as fabric items, as the rigid touch sensors may negatively impact feel and/or functionality of a soft-touch item.

To incorporate a touch sensor into a fabric item, layers of touch-sensing materials may be formed directly on the fabric. However, the structure of the fibers used to make fabrics and the porous, uneven surface morphology of fabrics may present challenges. For example, the fibers of the fabric may absorb the materials used for forming electrodes (e.g. conductive inks) of the touch sensor. This may make the deposition of thin, even layers of an electrode material challenging. Such absorption may be avoided by forming or adhering a substrate material to the fabric and then printing the electrodes on the substrate material, but the additional substrate layer may add undesired thickness to the touch sensor, and involves additional manufacturing steps.

Further, the porous surface morphology may present challenges in forming a dielectric layer between electrodes. For example, where the dielectric layer is deposited as a resin, the pores may provide locations for the formation of openings through the dielectric layer, which may pose a risngly, examples are disclosed that relate to touch sensors formed on fabric that may address such issues. Briefly, the disclosed examples provide touch sensors comprising an electrode layer formed directly on the fabric and a dielectric structure laminated over the electrode layer via an adhesive. Such a structure may allow the use of a thin and smooth dielectric layer that avoids the shorting risks described above. Further, the fabric may be formed from a coated fiber, or may otherwise comprise a coating, that may help to lessen the absorption of conductive inks used to print electrodes on the fabric and/or decrease a roughness of the fabric.