Wearable electronic device with fluid-based pressure sensing
An electronic device, such as a smart watch, incorporating a fluid-based pressure-sensing device is disclosed. The fluid-based pressure-sensing device includes an enclosure, a pressure sensor, a diaphragm and a sensing medium. The enclosure includes an opening and the pressure sensor is disposed inside the enclosure. The diaphragm hermetically seals the opening, and the sensing medium transfers a pressure exerted on the diaphragm to the pressure sensor. The sensing medium can be liquid oil filling a space of the enclosure, and the diaphragm is a polymer material. The pressure-sensing device may sense an environmental pressure, which may be used by the electronic device to modify its operations, change information that is displayed, and so on.
1. An electronic watch, comprising:
a housing defining a volume and a channel coupling the volume to an external environment;
a display at least partially within the volume;
a cover adjacent the display and coupled to the housing; and
a pressure-sensing device within the volume, configured to measure a pressure of the volume, and comprising:
an enclosure;
an isolation diaphragm hermetically sealed to the enclosure;
a sensing medium within the enclosure; and
a pressure sensor encapsulated by the sensing medium; wherein
the channel is configured to equalize the pressure of the volume and a pressure of the external environment; and
the display is configured to display the pressure of the volume.
2. The electronic watch of claim 1 , wherein:
the sensing medium is a silicone oil;
the electronic watch further comprises a substrate coupled to the enclosure;
the enclosure, isolation diaphragm, and substrate cooperate to retain the silicone oil within the enclosure; and
the isolation diaphragm is configured to deform in response to a change in pressure, thereby moving the silicone oil.
3. The electronic watch of claim 1 , further comprising:
a crown configured to rotate and translate; wherein:
the pressure-sensing device is configured to measure the pressure of the volume in response to the crown rotating or translating; and
the display is configured to display the pressure of the volume in response to the crown rotating or translating.
4. The electronic watch of claim 1 , wherein the enclosure is coupled to the housing.
5. The electronic watch of claim 1 , further comprising a filter disposed in the channel and configured to reduce ingress of contaminants from the external environment to the volume.
6. The electronic watch of claim 1 , wherein the channel is an audio port configured to transmit sound through the housing.
7. The electronic watch of claim 1 , further comprising a processing unit configured to modify an operation of the electronic watch based on the pressure of the volume.
8. An electronic watch, comprising:
a housing defining a volume and a channel coupling the volume to an external environment;
a display at least partially within the volume and configured to display information;
a substrate coupled to the housing;
an oil-filled pressure-sensing device positioned within the volume and physically and electrically coupled to the substrate, the oil-filled pressure-sensing device comprising:
an enclosure;
a pressure sensor positioned within the enclosure; and
a diaphragm sealed to the enclosure, the diaphragm and oil configured to transmit a pressure within the volume to the pressure sensor;
a band coupled to the housing and configured to couple the housing to a wearer; and
a processing unit electrically coupled to the oil-filled pressure-sensing device and the display; wherein:
the processing unit is configured to control the display;
the processing unit is configured to receive an output from the oil-filled pressure-sensing device; and
the information displayed by the display changes based on the output.
9. The electronic watch of claim 8 , wherein the processing unit is further configured to change a function of the electronic watch based on the output.
10. The electronic watch of claim 8 , wherein:
the oil-filled pressure-sensing device is substantially filled with an incompressible silicone oil.
11. The electronic watch of claim 10 , wherein the diaphragm comprises polyimide, TEFLON, polyethylene, polypropylene, ePTFE, or a corrugated polymer.
12. The electronic watch of claim 11 , wherein the diaphragm further comprises:
a first metal layer coupled to a first side of the polyimide; and
a second metal layer coupled to a second side of the polyimide.
13. The electronic watch of claim 11 , wherein:
the enclosure is a metal enclosure; and
the diaphragm is coupled to the metal enclosure by soldering, brazing, welding, pressure-sensitive adhesive, a pressure-sensitive tape, an epoxy, an acrylic, or a silicone adhesive.
14. The electronic watch of claim 10 , wherein the diaphragm is hydrophobic or oleophobic.
15. The electronic watch of claim 8 , wherein:
the oil-filled pressure-sensing device has a height and a width; and
a ratio of the height to the width is no more than 1 to 3.
16. The electronic watch of claim 8 , further comprising a crown configured to move relative to the housing; wherein:
the oil-filled pressure-sensing device generates the output in response to a motion of the crown.
17. An electronic watch, comprising:
a housing;
a band coupled to the housing and configured to couple the housing to a wearer;
a pressure-sensing device, comprising:
an enclosure coupled to the housing;
a diaphragm coupled to the enclosure;
a pressure sensor within the enclosure; and
a sensing medium within the enclosure and configured to encapsulate the pressure sensor;
a battery coupled to the pressure-sensing device; and
a processing unit coupled to the pressure-sensing device; wherein:
the pressure-sensing device is configured to measure a pressure of an external environment;
the battery is configured to supply power to the pressure-sensing device and the processing unit; and
the processing unit is configured to adjust an operation of the electronic watch based on the pressure of the external environment.
18. The electronic watch of claim 17 , wherein:
the enclosure comprises at least one of metal or ceramic;
the diaphragm comprises polyimide; and
the sensing medium comprises a silicone fluid.
19. The electronic watch of claim 18 , wherein the diaphragm further comprises metal coupled to the polyimide.
20. The electronic watch of claim 17 , further comprising a display configured to display the pressure of the external environment.