Strain sensor element and blood pressure sensor

A strain sensor element comprising:

• a plurality of strain sensor elements, each strain sensor element comprising:
• a laminated film comprising:
• a free layer comprising a magnetization having a magnetization direction which lies substantially perpendicularly to a plane direction of the laminated film under a condition of no external stress being applied;
• a reference layer comprising a magnetization;
• and
• a spacer layer provided between the free layer and the reference layer;
• a pair of electrodes configured to cause a current to flow through the laminated film in parallel with the plane direction thereof;
• and
• a substrate provided to contact both of the pair of electrodes,
• wherein a rotation angle of the magnetization of the free layer in response to a distortion of the substrate is different from a rotation angle of the magnetization of the reference layer in response to distortion of the substrate, and
• wherein the plurality of strain sensor elements are connected in series.

A blood pressure sensor comprising:

• a strain sensor element comprising:
• a laminated film comprising:
• a free layer comprising a magnetization having a magnetization direction which lies substantially perpendicularly to a plane direction of the laminated film under a condition of no external stress being applied;
• a reference layer comprising a magnetization;
• and
• a spacer layer provided between the free layer and the reference layer;
• a pair of electrodes configured to cause a current to flow through the laminated film in parallel with the plane direction thereof;
• and
• a substrate provided to contact both of the pair of electrodes,
• wherein a rotation angle of the magnetization of the free layer in response to a distortion of the substrate is different from a rotation angle of the magnetization of the reference layer in response to distortion of the substrate.