Pressure sensor device and method of sensing pressure

1. A pressure sensor device comprising:

a device package configured to define a cavity having an opening for fluid communication with an internal volume thereof, the cavity comprising a side wall;

an elongate pressure sensor element having a proximal end and a distal end; wherein

the side wall is configured to hold fixedly the proximal end of the pressure sensor element therein and

wherein

the pressure sensor element includes a closed cavity therein,

a substrate layer comprising a recessed portion formed therein, the recessed portion defining an open sensor element cavity portion;

a membrane layer disposed adjacent the substrate layer, the substrate laver and the membrane layer cooperating to close the open sensor element cavity portion and to define the closed cavity; and

the closed cavity is held fixedly by the side wall so that the pressure sensor element is cantilever-suspended from the side wall within the cavity.

2. The device according to claim 1 , wherein the side wall substantially surrounds the proximal end of the pressure sensor element.

3. The device according to claim 1 , wherein the pressure sensor element is surrounded by a fluid.

4. The device according to claim 3 , wherein the fluid is a liquid or a gelatinous material.

5. The device according to claim 1 , wherein the pressure sensor element comprises a closed cavity therein.

6. The device according to claim 5 , wherein the pressure sensor element comprises:

a substrate layer; and

a membrane layer disposed adjacent the substrate layer, the substrate layer and the membrane layer cooperating to define the closed cavity.

7. The device according to claim 6 , wherein the substrate layer comprises a recessed portion formed therein, the recessed portion defining an open sensor element cavity portion.

8. The device according to claim 7 , wherein the membrane layer is arranged to close the open sensor element cavity portion.

9. The device according to claim 1 , wherein the device package comprises a mating surface for fixing to a counterpart mating surface when in use, wherein the mating surface defines the opening of the cavity of the device package and is a keying surface.

10. The device according to claim 9 , wherein the keying surface is a roughened surface.

11. The device according to claim 1 , wherein the pressure sensor element is a Micro Electromechanical Systems element.

12. The device according to claim 1 , wherein the pressure sensor element is formed from two wafers.

13. The device according to claim 6 , wherein the membrane is configured to separate, when in use, an internal volume of the closed cavity from a medium under test.

14. The device according to claim 5 , wherein an internal pressure of the closed cavity defines a reference pressure.

15. An absolute pressure sensor device comprising the pressure sensor according to claim 1 .

16. An automotive vehicle comprising the pressure sensor device according to claim 1 .

17. A method of sensing pressure, the method comprising:

providing a device package defining a cavity having an opening for fluid communication with an internal volume thereof, the cavity having a side wall, the side wall holding an elongate pressure sensor element fixedly at a first end of the pressure sensor element;

providing a substrate layer and forming a recessed portion therein to define an open sensor element cavity portion;

disposing a membrane layer adjacent the substrate layer, the substrate layer and the membrane layer cooperating to close the open sensor element cavity portion and to define a closed cavity; and

the side wall holding fixedly the elongate pressure sensor element comprising the closed cavity so that the pressure sensor element is cantilever-suspending within the cavity.