# US 12,761,091 B2 · Pressure-sensitive ink, flexible pressure sensing structure, and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,091 B2 - Document ID: US12761091B2 - Status: Granted - Kind: B2 - Application number: 18/384,531 - Filed: 2023-10-27 - Published: 2025-05-01 - Granted: 2026-10-13 - Earliest claimed: 2023-10-27 - Assignees: Avary Holding (Shenzhen) Co., Limited.; Qing Ding Precision Electronics (Huaian) Co., Ltd; Garuda Technology Co., Ltd. - Applicants: Avary Holding (Shenzhen) Co., Limited.; Qing Ding Precision Electronics (Huaian) Co., Ltd; Garuda Technology Co., Ltd. - Inventors: Kuan-Ying Chen; Hsiao-Ting Hsu; Fu-Yun Shen - Web page: https://patentgrep.com/patent/US12761091B2 ## CPC - G01L 1/18: using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material - G01L 1/2275: {for non linearity} - G01L 1/2287: {constructional details of the strain gauges (adjustable resistors H01C10/00)} - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract A pressure-sensitive ink includes an adhesive, conductive particles, and inorganic fillers dispersed in the adhesive. The inorganic fillers include hydrophobic groups, and the inorganic fillers can increase the dispersibility of the conductive particles. The conductive particles can be uniformly dispersed in the adhesive by adding inorganic fillers with hydrophobic groups. The sensitivity and structure stability of a flexible pressure sensing structure are improved, and the noise of the flexible pressure sensing structure is reduced. In addition, the stability and the process yield of the flexible pressure sensing structure are also improved A flexible pressure sensing structure and an electronic device are also disclosed. ## Claims ### Claim 1 A pressure-sensitive ink, comprising: an adhesive; conductive particles dispersed in the adhesive; and inorganic fillers dispersed in the adhesive, wherein the inorganic fillers comprise hydrophobic groups, each of the inorganic fillers further comprises a core and a shell on the core, the hydrophobic groups are connected to a surface of the shell, and the core defines at least one hollow structure. ### Claim 2 (depends on 1) The pressure-sensitive ink of claim 1, wherein the core defines a plurality of hollow structures, each of the plurality of hollow structures is a microporous structure. ### Claim 3 (depends on 1) The pressure-sensitive ink of claim 1, wherein a dielectric constant of each of the inorganic fillers is less than or equal to 3. ### Claim 4 (depends on 1) The pressure-sensitive ink of claim 1, wherein an average particle size of each of the inorganic fillers ranges from 10 nm to 100 nm. ### Claim 5 (depends on 1) The pressure-sensitive ink of claim 1, wherein each of the hydrophobic groups comprises at least one of fluorine atom, methyl, ethyl, and propyl. ### Claim 6 (depends on 1) The pressure-sensitive ink of claim 1, wherein a weight percentage of the inorganic fillers in the pressure-sensitive ink ranges from 5 wt. % to 10 wt. %. ### Claim 7 A flexible pressure sensing structure, comprising: an insulating layer, a pressure strain layer, and a conductive layer stacked in a sequential order, wherein the pressure strain layer comprises: a matrix; conductive particles dispersed in the matrix; and inorganic fillers dispersed in the matrix, wherein the inorganic fillers comprise hydrophobic groups, each of the inorganic fillers further comprises a core and a shell on the core, the hydrophobic groups are connected to a surface of the shell, and the core defines at least one hollow structure. ### Claim 8 (depends on 7) The flexible pressure sensing structure of claim 7, wherein the core defines a plurality of hollow structures, each of the plurality of hollow structures is a microporous structure. ### Claim 9 (depends on 7) The flexible pressure sensing structure of claim 7, wherein a dielectric constant of each of the inorganic fillers is less than or equal to 3. ### Claim 10 (depends on 7) The flexible pressure sensing structure of claim 7, wherein an average particle size of each of the inorganic fillers ranges from 10 nm to 100 nm. ### Claim 11 (depends on 7) The flexible pressure sensing structure of claim 7, wherein each of the hydrophobic groups comprises at least one of fluorine atom, methyl, ethyl, and propyl. ### Claim 12 (depends on 7) The flexible pressure sensing structure of claim 7, wherein a weight percentage of the inorganic fillers in the pressure strain layer ranges from 5 wt. % to 10 wt. %. ### Claim 13 (depends on 7) The flexible pressure sensing structure of claim 7, wherein the flexible pressure sensing structure is a strain type pressure sensor. ### Claim 14 (depends on 7) The flexible pressure sensing structure of claim 7, wherein a change rate of resistance of the flexible pressure sensing structure is less than or equal to 20%, and a noise of the flexible pressure sensing structure is 1.2±0.5. ### Claim 15 An electronic device, comprising: a circuit board comprising at least one flexible pressure sensing structure, each of the at least one flexible pressure sensing structure comprising: an insulating layer, a pressure strain layer, and a conductive layer stacked in a sequential order, wherein the pressure sensing layer is electrically connected to a circuit layer of the circuit board through the conductive layer, the pressure strain layer comprising: a matrix; conductive particles dispersed in the matrix; and inorganic fillers dispersed in the matrix, wherein the inorganic fillers comprise hydrophobic groups, each of the inorganic fillers further comprises a core and a shell on the core, the hydrophobic groups are connected to a surface of the shell, and the core defines at least one hollow structure. ### Claim 16 (depends on 15) The electronic device of claim 15, wherein a dielectric constant of each of the inorganic fillers is less than or equal to 3. ### Claim 17 (depends on 15) The electronic device of claim 15, wherein a weight percentage of the inorganic fillers in the pressure strain layer ranges from 5 wt. % to 10 wt. %.