US-12618727-B2 - Smart fabric impact sensors

Abstract

A force sensing device, pressure sensing matrix, and article of manufacture include resistive sensing elements. The pressure sensing matrix includes multiple force sensing devices for detecting a location of an applied force. Each force sensing device includes a resistive sensing element (RSE). The RSE includes a closed cell foam structure having a cavity for receiving a core portion. The core portion includes an open-cell foam. The core portion includes carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE. The RSE generates a voltage signal in response to a force impacting the RSE. A conductive foil layer disposed on each of the opposing sides of the RSE for conducting the voltage signal to a conductive thread. The conductive thread is in electrical communication with the respective foil layer for transmitting voltage data to an external microprocessor device for processing.

Inventors

• Arar Salim ALKHADER

Assignees

• Arar Salim ALKHADER

Dates

Publication Date

20260505

Application Date

20240129

Claims (20)

1. 1 . A force sensing device comprising: a resistive sensing element (RSE), the RSE comprising: a closed cell foam structure having a cavity for receiving a core portion; the core portion comprising an open-cell foam having carbon particles impregnated therein; the core portion comprising carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE, the RSE generating a voltage signal in response to a force impacting the RSE; and a conductive foil layer disposed on each of an opposing side of the RSE for conducting the voltage signal to a conductive thread, the conductive thread in electrical communication with the respective foil layer for transmitting a voltage data to an external microprocessor device for processing.
2. 2 . The force sensing device of claim 1 , wherein the closed-cell foam structure comprises a laminated polyethylene PE foam structure.
3. 3 . The force sensing device of claim 1 , wherein the cavity being disposed in a center of the closed-cell foam structure.
4. 4 . The force sensing device of claim 1 , wherein the core portion comprises a polyethylene (PU) foam structure.
5. 5 . The force sensing device of claim 4 , wherein the core portion further comprises a semiconductive polymeric structure.
6. 6 . The force sensing device of claim 1 , wherein the closed-cell foam structure having a first thickness, and the core portion having a second thickness.
7. 7 . The force sensing device of claim 6 , wherein the first thickness is the same as the second thickness.
8. 8 . The force sensing device of claim 6 , wherein the second thickness is greater than the first thickness.
9. 9 . The force sensing device of claim 8 , wherein the core portion having the second thickness extends above at least one surface of the closed cell foam, the core portion forming a gap between the conductive foil layer and the RSE.
10. 10 . A pressure sensing matrix comprising a plurality of force sensing devices for detecting a location of an applied force; each force sensing device of the plurality of force sensing devices comprising: a resistive sensing element (RSE), the RSE comprising: a closed cell foam structure having a cavity for receiving a core portion; the core portion comprising an open-cell foam having carbon particles impregnated therein; the core portion comprising carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE, the RSE generating a voltage signal in response to a force impacting the RSE; and a conductive foil layer disposed on each of an opposing side of the RSE for conducting the voltage signal to a conductive thread, the conductive thread in electrical communication with the respective foil layer for transmitting a voltage data to an external microprocessor device for processing.
11. 11 . The pressure sensing matrix of claim 10 , wherein the pressure sensing matrix comprising a plurality of force sensing devices arranged in subdivided areas; wherein each force sensing device senses the force independently from another force sensing device of the plurality of force sensing devices; each force sensing device generating a voltage response to the sensed force and detects the amount and the location of the force through the respective conductive thread.
12. 12 . The pressure sensing matrix of claim 10 , wherein the pressure sensing matrix comprising a plurality of independent force sensing devices, sensor array; wherein each force sensing devices of the plurality of independent force sensing devices senses the force independently of other sensors in the pressure sensing matrix, and provides a feedback signal indicating an amount and location of the force through the respective one of the foil layers via conductive threads in electrical communication with other force sensing devices of the pressure sensing matrix.
13. 13 . The pressure sensing matrix of claim 11 , wherein the conductive thread comprises a continuously drawn 3-ply stainless steel conductive thread.
14. 14 . The pressure sensing matrix of claim 12 , wherein the conductive thread is hand-sewn between the conductive foil layer and an electrically insulating sheet on opposing sides of force sensor.
15. 15 . An article of manufacture comprising a pressure sensing matrix, comprising: a plurality of force sensing devices; each force sensing device of the plurality of force sensing devices comprising: a resistive sensing element (RSE), the RSE comprising: a closed cell foam structure having a cavity for receiving a core portion; the core portion comprising an open-cell foam having carbon particles impregnated therein; the core portion comprising carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE, the RSE generating a voltage signal in response to a force impacting the RSE; and a conductive foil layer disposed on each of an opposing side of the RSE for conducting the voltage signal to a conductive thread, the conductive thread in electrical communication with the respective foil layer for transmitting a voltage data to an external microprocessor device for processing.
16. 16 . The article of manufacture of claim 15 , wherein the article of manufacture comprises a helmet; and a fabric sheet comprising the pressure sensing matric and being interconnected via conductive thread; the fabric sheet attached to a surface of the helmet.
17. 17 . The article of manufacture of claim 16 , wherein the fabric sheet being mounted externally of the helmet; and wherein the force sensing devices sense one or more forces independently of other force sensing devices of the pressure sensing matrix.
18. 18 . The article of manufacture of claim 16 , wherein the fabric sheet being inserted within an internal padding of the helmet; and wherein the force sensing devices sense one or more forces independently of other force sensing devices of the pressure sensing matrix.
19. 19 . The article of manufacture of claim 16 , wherein each force sensing device of the plurality of force sensing devices further comprises a hard intender case covering the force sensing device; and an LED to provide a color shade corresponding to an impact force range.
20. 20 . The article of manufacture of claim 15 , wherein the article of manufacture being selected from one of the group consisting of: textile fabric and tactile mapping material; body mapping material; mattress, seat belt, crash testing apparatus, military body armor, gloves and exercise attire.

Description

BACKGROUND OF THE INVENTION The present disclosure relates to smart fabric impact sensors. More particularly the disclosure relates to smart fabric impact sensors comprising semiconductive polymer composites and applications for use of same to determine impact magnitudes and locations. Smart Fabric Sensors (SFSs) have recently gained much interest as they are convenient as a long-term wearable that may be incorporated into apparel. In addition, SFSs feature properties such as simplicity, lightweight, low manufacturing cost, high sensitivity, and flexibility. Semiconductive polymer composites, or SCPCs, can be used as smart fabrics to create force or pressure sensors based on the piezoresistive effect. Wider application of SCPCs may be limited due to their characteristically narrow sensing range, hysteresis and output drift issues. Research studying voltage response related errors of SCPCs, particularly when applied under high impact forces, is needed. What is needed is a system and/or method that combines the benefits of SFSs and SCPCs, satisfies one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs. SUMMARY OF THE INVENTION One embodiment relates to a force sensing device. The force sensing device includes a resistive sensing element (RSE). The RSE includes a closed cell foam structure having a cavity for receiving a core portion. The core portion includes an open-cell foam. The core portion includes carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE. The RSE generates a voltage signal in response to a force impacting the RSE. A conductive foil layer disposed on each of the opposing sides of the RSE for conducting the voltage signal to a conductive thread. The conductive thread is in electrical communication with the respective foil layer for transmitting voltage data to an external microprocessor device for processing. Another embodiment relates to a pressure sensing matrix. The pressure sensing matrix includes multiple force sensing devices for detecting a location of an applied force. Each force sensing device includes a resistive sensing element (RSE). The RSE includes a closed cell foam structure having a cavity for receiving a core portion. The core portion includes an open-cell foam. The core portion includes carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE. The RSE generates a voltage signal in response to a force impacting the RSE. A conductive foil layer disposed on each of the opposing sides of the RSE for conducting the voltage signal to a conductive thread. The conductive thread is in electrical communication with the respective foil layer for transmitting voltage data to an external microprocessor device for processing. In yet another embodiment, an article of manufacture incorporating a pressure sensing matrix is disclosed. The pressure sensing matrix includes multiple force sensing devices for detecting a location of an applied force. Each force sensing device includes a resistive sensing element (RSE). The RSE includes a closed cell foam structure having a cavity for receiving a core portion. The core portion includes an open-cell foam. The core portion includes carbon black particles dispersed therein to form a semiconductive polymeric structure and piezoresistive RSE. The RSE generates a voltage signal in response to a force impacting the RSE. A conductive foil layer disposed on each of the opposing sides of the RSE for conducting the voltage signal to a conductive thread. The conductive thread is in electrical communication with the respective foil layer for transmitting voltage data to an external microprocessor device for processing. Certain advantages of the embodiments described herein include designs of a smart fabric force sensor for wearable applications. Disclosed sensors have been shown to obtain the general characterization of their behavior through many tests and protocols for force-voltage response, linearity, hysteresis, and output drift under various loads ranging from 1 to 50 newtons (N). A polyurethane (PU) open-cell foam impregnated with carbon black particles may serve as a resistive sensing element with a combination of other fabrics. Another advantage is a polyethylene foam with a core of carbon black PU foam resistive sensing element (RSE) layer. Still another advantage includes a polyethylene border layer with a core of carbon black polyurethane foam having a compressed RSE of extra 3 mm thickness of PU foam from both sides. RSE sensor devices exhibit acceptable ranges compared to commercially available sensors. RSE sensors provide a wide sensing range that demonstrates reputable dete