Three Patently Apple reports this month covered the development of smart fabrics for various future devices and clothing (01, 02 & 03).  Our fourth patent report of the month on smart fabrics comes by way of a newly granted patent for Apple issued today by the U.S. Patent and Trademark Office regarding fusible insulating strands.

Fabric-Based items with Fusible Insulating Strands

Apple states that it may be desirable to form items such a bags, clothing, and other items from intertwined strands of material. For example, woven or knitted fabric or braided strands may be used in forming portions of an item.

In some situations, it may be desirable for some or all of a strand of material in an item to be conductive. Conductive strands may be used, for example, to carry signals between circuitry in different portions of an item. Strands such as conductive strands may serve mechanical functions (e.g., by forming a part of a fabric) and/or electrical functions (e.g., by conveying signals).

Challenges may arise when forming items such as fabric-based items with conductive strands. It is often desirable for conductive strands to exhibit good mechanical properties, such as high strength and flexibility. Because conductive strands may need to carry electrical signals, the resistance of a conductive strand should generally not be too high.

Conductive strands should also be compatible with the non-conductive strands in a fabric and should not form undesired short circuits with surrounding structures. If care is not taken, conductive strands in a fabric-based item may be overly fragile, may exhibit poor signal carrying capabilities, may be insufficiently isolated from surrounding structures, or may adversely affect the appearance and feel of the item.

Apple's invention covers an item that may include fabric or other materials formed from intertwined strands of material. The item may include circuitry that produces signals. The strands of material may include non-conductive strands and conductive strands.

More specifically, Apple states that item #10 of FIG. 1 below may be an electronic device or an accessory for an electronic device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user's head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which fabric-based item 10 is mounted in a kiosk, in an automobile, airplane, or other vehicle.

In addition, other electronic equipment can include may be a removable external case for electronic equipment, may be a strap, may be a wrist band or head band, may be a removable cover for a device, may be a case or bag that has straps or that has other structures to receive and carry electronic equipment and other items, may be a necklace or arm band, may be a wallet, sleeve, pocket, or other structure into which electronic equipment or other items may be inserted, may be part of a chair, sofa, or other seating (e.g., cushions or other seating structures), may be part of an item of clothing or other wearable item (e.g., a hat, belt, wrist band, headband, etc.), or may be any other suitable strand-based item.

Apple adds that these devices contain conductive strands that may carry signals produced by the circuitry. Each conductive strand may have a conductive core that carries electrical signals. The conductive core may be a solid conductive core or may be formed from a non-conductive inner core that has been covered with a conductive coating. In arrangements where the conductive core is formed from a non-conductive inner core that has been covered with a conductive material, the non-conductive inner core may be formed from polymers such as para-aramids and aromatic polyesters (as examples). The conductive coating may be formed from a metal such as silver or other metals.

To mechanically and electrically insulate and isolate conductive strands, insulating material may surround the conductive core of the conductive strands. Examples of materials that may be used for forming the insulator include polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, polyurethane, and other polymers.

In some arrangements, the insulating material may be a relatively thin insulator coating such as an insulator coating with a thickness of less than 5 microns or other suitable thickness. In some arrangements, the insulating material may be formed from non-conductive strands that have been wrapped around the conductive core to electrically insulate the conductive core and protect the conductive core from moisture and other contaminants. Fabric-based items that include a combination of insulating coatings and insulating strands may also be used.

Inner polymer strand cores may be formed by extrusion, spinning, or other techniques. Metal coatings for the inner strand cores may be formed by electrochemical deposition or other metal deposition techniques.

Insulating strands may include strands of fusible material that softens when heated to the appropriate temperature. Fusible insulating strands may be interspersed with insulating strands of a different material. The fusible insulating strands may be heated such that the fusible material melts and fills gaps between the other insulating strands, thereby forming a watertight covering over the conductive strand. The fusible insulating strands may be used to insulate electrical connections between conductive strands and/or between electronic components and conductive strands.

Apple's patent FIG. 1 below is a schematic diagram of an illustrative item that may include strands of material; FIG. 11 is a side view of an illustrative conductive strand that is wrapped with non-conductive strands of different materials.

Apple's patent FIG. 16 above is a cross-sectional side view of the conductive strand of FIG. 15 in which the fusible insulating strand has been fused around the conductive strand and electronic component; FIG. 18 is a flow chart of illustrative steps involved in mounting an electronic component to a conductive strand that is partially covered with fused insulating strands.

After wrapping conductive strands in insulating strands an electronic component such as electronic component may be mounted to conductive strands.

Electrical components within smart fabrics may include connectors, input-output devices such as switches, buttons, light-emitting components such as light-emitting diodes, audio components such as microphones and speakers, vibrators (e.g., piezoelectric actuators that can vibrate), solenoids, electromechanical actuators, motors, and other electromechanical devices, microelectromechanical systems (MEMs) devices, pressure sensors, light detectors, proximity sensors (light-based proximity sensors, capacitive proximity sensors, etc.), force sensors (e.g., piezoelectric force sensors), strain gauges, moisture sensors, temperature sensors, accelerometers, gyroscopes, compasses, magnetic sensors (e.g., Hall effect sensors and magnetoresistance sensors such as giant magnetoresistance sensors), touch sensors, and other sensors, components that form displays.

Electrical components may also include touch sensors arrays (e.g., arrays of capacitive touch sensor electrodes to form a touch sensor that detects touch events in two dimensions), and other input-output devices, electrical components that form control circuitry such as non-volatile and volatile memory, microprocessors, application-specific integrated circuits, system-on-chip devices, baseband processors, wired and wireless communications circuitry, and other integrated circuits.

For more details, review Apple's granted patent 10,472,742 which was originally filed in Q1 2017 and published today by the US Patent and Trademark Office.