Active humidity control using heat-responsive water-releasing substances in data storage devices

1 . A method of adjusting a humidity within an interior of an enclosure of a data storage device, the method comprising:

detecting a trigger condition; and

in response to detecting the trigger condition, heating a water-releasing substance situated within the interior of the enclosure of the data storage device to release water, thereby increasing the humidity within the interior of the enclosure of the data storage device, wherein the water-releasing substance comprises sodium percarbonate (Na 2 CO 3 · 1.5H 2 O 2 ).

2 . The method of claim 1 , wherein the trigger condition is that a particular amount of time has passed, the particular amount of time being an amount of time that (a) the data storage device has been in operation, or (b) a laser of a heat-assisted magnetic recording (HAMR) head has been in operation.

3 . The method of claim 1 , wherein the trigger condition comprises one or more of:

a recording head of the data storage device has remained or will remain over a single track of a recording medium of the data storage device for a threshold amount of time,

an adjacent track interference (ATI) refresh command or operation,

a formatting command or operation,

the humidity within the interior of the enclosure of the data storage device is below a threshold, or

a command or instruction.

4 . The method of claim 1 , wherein the trigger condition is a first trigger condition, and further comprising:

detecting a second trigger condition, the second trigger condition being different from the first trigger condition; and

in response to detecting the second trigger condition, heating the water-releasing substance a second time, thereby increasing the humidity within the interior of the enclosure of the data storage device.

5 . The method of claim 4 , wherein heating the water-releasing substance the second time comprises heating the water-releasing substance to a different temperature than when heating the water-releasing substance in response to detecting the first trigger condition.

6 . The method of claim 4 , wherein:

the first trigger condition is that a specified amount of time has passed since the data storage device was placed into service; and

the second trigger condition is that a recording head of the data storage device will remain over a track of a recording medium of the data storage device for at least a threshold amount of time.

7 . The method of claim 4 , wherein:

the first trigger condition is that a specified amount of time has passed since the data storage device was placed into service; and

the second trigger condition is an adjacent track interference (ATI) refresh operation.

8 . The method of claim 4 , further comprising at least one of:

monitoring for the first trigger condition; or

monitoring for the second trigger condition.

9 . The method of claim 1 , further comprising:

monitoring for the trigger condition.

10 . The method of claim 9 , wherein monitoring for the trigger condition comprises at least one of:

measuring or estimating a current humidity within the interior of the enclosure,

monitoring a service time of the data storage device,

monitoring an operation time of a laser of a heat-assisted magnetic recording (HAMR) head of the data storage device,

monitoring a communication channel for an instruction, or

reading a register.

11 . A method of adjusting a humidity within an interior of an enclosure of a data storage device, the method comprising:

detecting a trigger condition; and

in response to detecting the trigger condition, heating a water-releasing substance situated within the interior of the enclosure of the data storage device to release water, thereby increasing the humidity within the interior of the enclosure of the data storage device,

wherein:

the water-releasing substance is situated in a core area of a voice coil winding of the data storage device; and

heating the water-releasing substance situated within the interior of the enclosure of the data storage device comprises causing current to flow through the voice coil winding.

12 . The method of claim 11 , wherein the trigger condition is that a particular amount of time has passed, wherein the particular amount of time is an amount of time that (a) the data storage device has been in operation, or (b) a laser of a heat-assisted magnetic recording (HAMR) head has been in operation.

13 . The method of claim 11 , wherein the trigger condition comprises one or more of:

a recording head of the data storage device has remained or will remain over a single track of a recording medium of the data storage device for a threshold amount of time,

an adjacent track interference (ATI) refresh command or operation,

a formatting command or operation,

the humidity within the interior of the enclosure of the data storage device is below a threshold, or

a command or instruction.

14 . The method of claim 11 , wherein the trigger condition is a first trigger condition, and further comprising:

detecting a second trigger condition, the second trigger condition being different from the first trigger condition; and

in response to detecting the second trigger condition, heating the water-releasing substance a second time, thereby increasing the humidity within the interior of the enclosure of the data storage device.

15 . The method of claim 14 , wherein:

the first trigger condition is that a specified amount of time has passed since the data storage device was placed into service; and

the second trigger condition is that a recording head of the data storage device will remain over a track of a recording medium of the data storage device for at least a threshold amount of time.

16 . The method of claim 14 , wherein:

the first trigger condition is that a specified amount of time has passed since the data storage device was placed into service; and

the second trigger condition is an adjacent track interference (ATI) refresh operation.

17 . A data storage device, comprising:

a water-releasing substance;

a heater configured to heat the water-releasing substance; and

a controller configured to, in response to an occurrence of a trigger condition, control the heater to increase a temperature of the water-releasing substance to cause the water-releasing substance to release water, wherein the water-releasing substance comprises sodium percarbonate (Na 2 CO 3 · 1.5H 2 O 2 ).

18 . The data storage device recited in claim 17 , wherein the trigger condition comprises passage of a specified amount of time.

19 . The data storage device recited in claim 18 , wherein:

the specified amount of time is an operation time of a laser of a heat-assisted magnetic recording (HAMR) head of the data storage device; and

the controller is further configured to determine the operation time of the laser of the heat-assisted magnetic recording (HAMR) head of the data storage device.

20 . The data storage device recited in claim 17 , wherein:

the trigger condition comprises occurrence of a command; and

the controller is further configured to detect or issue the command.

21 . The data storage device recited in claim 20 , wherein the command comprises an adjacent track interference (ATI) refresh command.

22 . The data storage device recited in claim 17 , further comprising:

a water-absorbing material, wherein the water-absorbing material comprises at least one of a desiccant, calcium peroxide (CaO 2 ), magnesium peroxide (MgO 2 ), sodium peroxide (Na 2 O 2 ), or a hydrogel.

23 . A data storage device, comprising:

a water-releasing substance;

a heater configured to heat the water-releasing substance; and

a controller configured to, in response to an occurrence of a trigger condition, control the heater to increase a temperature of the water-releasing substance to cause the water-releasing substance to release water,

wherein:

the water-releasing substance is situated in a core area of a voice coil winding of the data storage device; and

the heater comprises the voice coil winding.

24 . The data storage device recited in claim 23 , wherein the water-releasing substance comprises one or more of: an inorganic hydrate, a hydrate of metal sulfate, a hydrate of metal nitrate, an inorganic halide, an organic hydrate, a gas hydrate, a salt compound that is compounded with hydrogen peroxide, a superabsorbent polymer, a hygroscopic salt, a zeolite, a silica gel, montmorillonite, a hydrogel, lithium chloride, or a metal-organic framework (MOF).

25 . The data storage device recited in claim 23 , further comprising a current source coupled to the controller and to the voice coil winding, and wherein controlling the heater to increase the temperature of the water-releasing substance comprises controlling the current source to cause a current to flow through the voice coil winding.

26 . The data storage device recited in claim 23 , wherein the trigger condition comprises passage of a specified amount of time, wherein:

the specified amount of time is an operation time of a laser of a heat-assisted magnetic recording (HAMR) head of the data storage device; and

the controller is further configured to determine the operation time of the laser of the heat-assisted magnetic recording (HAMR) head of the data storage device.

27 . The data storage device recited in claim 23 , wherein:

the trigger condition comprises occurrence of a command; and

the controller is further configured to detect or issue the command.

28 . The data storage device recited in claim 27 , wherein the command comprises an adjacent track interference (ATI) refresh command.

29 . The data storage device recited in claim 23 , further comprising:

a water-absorbing material, wherein the water-absorbing material comprises at least one of a desiccant, calcium peroxide (CaO 2 ), magnesium peroxide (MgO 2 ), sodium peroxide (Na 2 O 2 ), or a hydrogel.