Pressure sensor

A pressure sensor, comprising:

• a substrate;
• a functional element which is laid on the substrate and is composed of functional titanium oxide including crystal grains of at least one of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) and having the property that at least a portion of crystal grains of at least one of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher;
• and
• one or more electrodes disposed on a surface of the functional element and one or more electrodes disposed in an interface between the substrate and functional element,
• wherein:
• the substrate includes a substrate thin-film section having a thin film form in which the thickness in the stacking direction of the substrate and the functional element is smaller than that in the other directions, and
• an average grain size of the crystal grains of the functional titanium oxide is 5 to 50 nm.

A pressure sensor, comprising:

• a pressure sensor body including a functional element that has a composition of trititanium pentoxide (Ti3O5) and changes in physical property with a change in pressure when pressurized at 1 MPa or higher, wherein
• the functional element is composed of functional titanium oxide which includes crystal grains of at least λ-phase trititanium pentoxide (λ-Ti3O5) when not pressurized and has the property that at least a portion of the crystal grains of λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of β-phase trititanium pentoxide (β-Ti3O5) when the functional titanium oxide is pressurized at 1 MPa or higher,
• the functional titanium oxide includes crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) at lower than 350° C. and includes the property that at least a portion of the crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher,
• the pressure sensor body further includes a base material and the functional element is contained in the base material,
• the base material is made of resin,
• the functional element is particles made of the functional titanium oxide, and
• the particles made of the functional titanium oxide are dispersed or interconnected in groups in the base material.

A pressure sensor, comprising

• a pressure sensor body including a functional element that has a composition of trititanium pentoxide (Ti3O5) and changes in physical property with a change in pressure when pressurized at 1 MPa or higher, wherein
• the functional element is composed of functional titanium oxide which includes crystal grains of at least λ-phase trititanium pentoxide (λ-Ti3O5) when not pressurized and has the property that at least a portion of the crystal grains of λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of β-phase trititanium pentoxide (β-Ti3O5) when the functional titanium oxide is pressurized at 1 MPa or higher,
• the functional titanium oxide includes crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) at lower than 350° C. and includes the property that at least a portion of the crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher,
• the pressure sensor body further includes a base material and the functional element is contained in the base material,
• the base material is a film,
• the functional element is particles made of the functional titanium oxide, and
• the particles made of the functional titanium oxide are dispersed or interconnected in groups in the base material.

A pressure sensor, comprising

• a pressure sensor body including a functional element that has a composition of trititanium pentoxide (Ti3O5) and changes in physical property with a change in pressure when pressurized at 1 MPa or higher, wherein
• the functional element is composed of functional titanium oxide which includes crystal grains of at least λ-phase trititanium pentoxide (λ-Ti3O5) when not pressurized and has the property that at least a portion of the crystal grains of λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of β-phase trititanium pentoxide (β-Ti3O5) when the functional titanium oxide is pressurized at 1 MPa or higher,
• the functional titanium oxide includes crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) at lower than 350° C. and includes the property that at least a portion of the crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher,
• the pressure sensor body further includes a base material and the functional element is contained in the base material,
• the base material is a sheet composed of woven or non-woven fabric,
• the functional element is particles made of the functional titanium oxide, and
• the particles made of the functional titanium oxide are dispersed or interconnected in groups in the base material.

A pressure sensor, comprising

• a pressure sensor body including a functional element that has a composition of trititanium pentoxide (Ti3O5) and changes in physical property with a change in pressure when pressurized at 1 MPa or higher, wherein
• the functional element is composed of functional titanium oxide which includes crystal grains of at least λ-phase trititanium pentoxide (λ-Ti3O5) when not pressurized and has the property that at least a portion of the crystal grains of λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of β-phase trititanium pentoxide (β-Ti3O5) when the functional titanium oxide is pressurized at 1 MPa or higher,
• the functional titanium oxide includes crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) at lower than 350° C. and includes the property that at least a portion of the crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher,
• the pressure sensor body further includes a base material and the functional element is contained in the base material,
• the base material is liquid or gel,
• the functional element is particles made of the functional titanium oxide, and
• the particles made of the functional titanium oxide are dispersed or interconnected in groups in the base material.

A pressure sensor, comprising:

• a substrate;
• and
• a functional element which is laid on the substrate and is composed of functional titanium oxide including crystal grains of at least one of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) and having the property that at least a portion of crystal grains of at least one of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher, wherein
• the substrate includes a substrate thin-film section having a thin film form in which the thickness in the stacking direction of the substrate and the functional element is smaller than that in the other directions, and
• an average grain size of the crystal grains of the functional titanium oxide is 5 to 50 nm.

A pressure sensor, comprising

• a pressure sensor body including a functional element that has a composition of trititanium pentoxide (Ti3O5) and changes in physical property with a change in pressure when pressurized at 1 MPa or higher,
• wherein the functional element is composed of functional titanium oxide which includes crystal grains of at least λ-phase trititanium pentoxide (λ-Ti3O5) when not pressurized and has the property that at least a portion of the crystal grains of λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of β-phase trititanium pentoxide (β-Ti3O5) when the functional titanium oxide is pressurized at 1 MPa or higher,
• the functional titanium oxide includes crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) at lower than 350° C. and includes the property that at least a portion of the crystal grains of β-phase trititanium pentoxide (β-Ti3O5) and λ-phase trititanium pentoxide (λ-Ti3O5) change into crystal grains of titanium dioxide (TiO2) when the functional titanium oxide is heated to 350° C. or higher, and
• an average grain size of the crystal grains of the functional titanium oxide is 5 to 50 nm.