Foam pressure sensor

1. A hybrid sensor comprising:

a first plate;

a second plate;

a foam disposed between the first and second plate;

wherein the first plate, the second plate and the foam are disposed relative to each other forming a foam capacitor:

a conductor clad piezoelectric film is disposed on a surface of one of the first or second plates forming a piezoelectric sensor;

wherein the piezoelectric sensor has a bandwidth, defined by an intrinsic RC time constant of the piezoelectric sensor, that is larger than a bandwidth of the foam capacitor, providing a hybrid sensor having a high bandwidth impact sensor via the piezoelectric sensor, and a lower bandwidth pressure sensor via the foam capacitor.

2. The hybrid sensor of claim 1 , wherein the foam has a density between 6 to 25 lbs/ft 3 .

3. The hybrid sensor of claim 1 , wherein the foam has a compression set of less than about 10%.

4. The hybrid sensor of claim 1 , wherein the foam has a force-deflection of between about 1-9 psi (7-63 kPa).

5. The hybrid sensor of claim 1 , wherein the plates are metallic.

6. The hybrid sensor of claim 1 , wherein the foam is a polyurethane foam having an average cell size of about 50 to 250 μm and a density of between 5 to 30 lbs/ft 3 .

7. The hybrid sensor of claim 1 , wherein the first plate, the second plate, and the foam, form a foam capacitor, and wherein the foam capacitor and the conductor clad piezoelectric film are electrically connected to provide a common ground between them.

8. The hybrid sensor of claim 7 , wherein the conductor clad piezoelectric film is connected between an analog to digital converter and the common ground.

9. The hybrid sensor of claim 7 , wherein the foam capacitor is connected between a capacitance sensor and the common ground.