Abstract:
In some embodiments, transpiration cooling for passive cooled ultra mobile personal computer is presented. In this regard, an apparatus is introduced having a plurality of integrated circuit device(s), a power source to power the integrated circuit device(s), a chassis to house the integrated circuit device(s) and the power supply, and a skin to cover the chassis, the skin comprising a waterproof layer configured to prevent water from contacting the integrated circuit device(s) and a water absorbent layer configured to absorb water. Other embodiments are also disclosed and claimed.

Description:
FIELD OF THE INVENTION 
   Embodiments of the present invention generally relate to the field of passive cooled devices and, more particularly, to transpiration cooling for passive cooled ultra mobile personal computer. 
   BACKGROUND OF THE INVENTION 
   The demand for more powerful handheld electronic devices presents problems in keeping the devices from getting too hot to handle. Passive cooling solutions are preferred, because consumers tend to dislike the noise of a fan. Generally, a cooling solution is considered unacceptable if the skin temperature is allowed to exceed 45 degrees Celsius. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements, and in which: 
       FIG. 1  is a graphical illustration of a cross-sectional view of an example passive cooled ultra mobile personal computer with transpiration cooling, in accordance with one example embodiment of the invention; 
       FIG. 2  is a graphical illustration of a cross-sectional view of the skin of the ultra mobile personal computer depicted in  FIG. 1 , in accordance with one example embodiment of the invention; 
       FIG. 3  is a graphical illustration of a cross-sectional view of the ultra mobile personal computer depicted in  FIG. 1  coupled with a water source, in accordance with one example embodiment of the invention; and 
       FIG. 4  is a block diagram of an example electronic appliance suitable for implementing transpiration cooling, in accordance with one example embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that embodiments of the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention. 
   Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. 
     FIG. 1  is a graphical illustration of a cross-sectional view of an example passive cooled ultra mobile personal computer with transpiration cooling, in accordance with one example embodiment of the invention. As shown, ultra mobile personal computer  100  includes one or more of skin  102 , chassis  104 , integrated circuit devices  106 , power supply  108 , display  110 , and surface  112 . 
   Skin  102 , as described in greater detail in reference to  FIG. 2 , provides transpiration cooling for ultra mobile personal computer  100 . In one embodiment skin  102  is configured to be held in a person&#39;s hand. Transpiration cooling, as used herein, is a cooling solution that removes heat through water evaporation, producing much better results than natural convection and radiation. While shown as surrounding chassis  104 , skin  102  may directly contact integrated circuit devices  106  and/or power supply  108 . 
   Chassis  104  represents a housing for integrated circuit devices  106  and power supply  108 . Chassis  104  may be comprised of metal and may provide attachment points for a printed circuit board (not shown). 
   Integrated circuit devices  106  represent functional components ultra mobile personal computer  100  and may use several watts of electricity when fully functioning that becomes heat. Integrated circuit devices  106  may be coupled with heatsinks, not shown. 
   Power supply  108  may be a rechargeable battery that provides electricity to integrated circuit devices  106 . Power supply  108  may have a charge that is depleted within a few hours of use, requiring a recharge. 
   Display  110  may be a liquid crystal display (LCD) that provides a graphical user interface for ultra mobile personal computer  100 . 
   Surface  112  may be included in ultra mobile personal computer  100  to provide a support when coupled with a water source, as depicted in  FIG. 3 . 
     FIG. 2  is a graphical illustration of a cross-sectional view of the skin of the ultra mobile personal computer depicted in  FIG. 1 , in accordance with one example embodiment of the invention. In accordance with one example embodiment, skin  102  includes one or more of water absorbent layer  202  sandwiched between waterproof layer  204  and outer layer  206 . 
   Water absorbent layer  202  represents a material or combination of materials capable of absorbing and at least temporarily holding water. In one embodiment, water absorbent layer  202  is a temperature sensitive hydro gel, such as the acrylic acid-grafted carboxymethyl cellulose described in  Water - Absorbing Characteristics of Acrylic Acid - Grafted Carboxymethyl Cellulose Synthesized by Photografting , Shin Kuwabara and Hitoshi Kubota, Journal of Applied Polymer Science, Vol. 60, 1965-1970 (1996). In one embodiment, water absorbent layer  202  has a water absorbency that varies with temperature. In one embodiment, the water absorbency of water absorbent layer  202  is higher at lower temperatures and lower at higher temperatures with a significant drop in water absorbency at about 30 degrees Celsius. In one embodiment, water absorbent layer  202  is a sponge. Water absorbent layer  202  may be able to absorb water from ambient air or may need to have liquid water added to it. 
   As ultra mobile personal computer  100  is being used and the temperature of its internal components increases, skin  102  will also get warmer. Water previously absorbed in water absorbent layer  202  may then be released, either due to a decreased absorbency of water absorbent layer  202  or otherwise. This released water may then evaporate and thereby remove some heat from skin  102 . In one embodiment, the thickness of water absorbency layer  202  is determined so as to provide a sufficient amount of water absorbency to ensure that the effects of transpiration cooling will be available at least until the battery would be expected to require a recharge. In one embodiment, water absorbency layer  202  is one millimeter thick. 
   Waterproof layer  204  prevents water from contacting integrated circuit devices  106  and power supply  108 . In one embodiment, waterproof layer  204  is plastic. In another embodiment, waterproof layer  204  is metal. In one embodiment, waterproof layer  204  is integrated with chassis  104 . 
   Outer layer  206  substantially covers water absorbent layer  202  and provides openings for water to move into and out from water absorbent layer  202 . In one embodiment outer layer  206  is plastic. In another embodiment outer layer  206  is rubber. As shown, outer layer  206  includes micro-pores  208  and input opening  210 . To prevent water from escaping from water absorbent layer  202  when ultra mobile personal computer  100  is not in use, outer layer  206  may include a cover (not shown) that may slide over or snap over the openings in outer layer  206 . 
   Micro-pores  208  may have a diameter sufficiently large enough to allow water to pass through and sufficiently small enough to prevent portions of water absorbent layer  202  from passing through. 
   Input opening  210  may have a funnel-shaped opening to allow water to be more easily added to water absorbent layer  202 . In one embodiment input opening  210  is configured to couple with a nozzle (not shown) of a water source. 
     FIG. 3  is a graphical illustration of a cross-sectional view of the ultra mobile personal computer depicted in  FIG. 1  coupled with a water source, in accordance with one example embodiment of the invention. As shown, ultra mobile personal computer  100  is coupled with water source  300  containing water  304 . Lip  302  of water source  300  supports surface  112  and thereby prevent ultra mobile personal computer  100  from entirely falling into water source  300 . Water  304  is able to enter water absorbent layer  202  of skin  102  through openings in outer layer  206 . Waterproof layer  204  prevents water  304  from contacting integrated circuit devices  106  or power supply  108 . 
     FIG. 4  is a block diagram of an example electronic appliance suitable for implementing transpiration cooling, in accordance with one example embodiment of the invention. Electronic appliance  400  is intended to represent any of a wide variety of traditional and non-traditional electronic appliances, laptops, cell phones, wireless communication subscriber units, personal digital assistants, or any electric appliance that would benefit from the teachings of the present invention. In accordance with the illustrated example embodiment, electronic appliance  400  may include one or more of processor(s)  402 , memory controller  404 , system memory  406 , input/output controller  408 , network controller  410 , and input/output device(s)  412  coupled as shown in  FIG. 4 . Electronic appliance  400  may be enclosed with a skin described previously as an embodiment of the present invention. 
   Processor(s)  402  may represent any of a wide variety of control logic including, but not limited to one or more of a microprocessor, a programmable logic device (PLD), programmable logic array (PLA), application specific integrated circuit (ASIC), a microcontroller, and the like, although the present invention is not limited in this respect. In one embodiment, processors(s)  402  are Intel® compatible processors. Processor(s)  402  may have an instruction set containing a plurality of machine level instructions that may be invoked, for example by an application or operating system. 
   Memory controller  404  may represent any type of chipset or control logic that interfaces system memory  406  with the other components of electronic appliance  400 . In one embodiment, the connection between processor(s)  402  and memory controller  404  may be referred to as a front-side bus. In another embodiment, memory controller  404  may be referred to as a north bridge. 
   System memory  406  may represent any type of memory device(s) used to store data and instructions that may have been or will be used by processor(s)  402 . Typically, though the invention is not limited in this respect, system memory  406  will consist of dynamic random access memory (DRAM). In one embodiment, system memory  406  may consist of Rambus DRAM (RDRAM). In another embodiment, system memory  406  may consist of double data rate synchronous DRAM (DDRSDRAM). 
   Input/output (I/O) controller  408  may represent any type of chipset or control logic that interfaces I/O device(s)  412  with the other components of electronic appliance  400 . In one embodiment, I/O controller  408  may be referred to as a south bridge. In another embodiment, I/O controller  408  may comply with the Peripheral Component Interconnect (PCI) Express™ Base Specification, Revision 1.0a, PCI Special Interest Group, released Apr. 15, 2003. 
   Network controller  410  may represent any type of device that allows electronic appliance  400  to communicate with other electronic appliances or devices. In one embodiment, network controller  410  may comply with a The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11b standard (approved Sep. 16, 1999, supplement to ANSI/IEEE Std 802.11, 1999 Edition). In another embodiment, network controller  410  may be an Ethernet network interface card. 
   Input/output (I/O) device(s)  412  may represent any type of device, peripheral or component that provides input to or processes output from electronic appliance  400 . 
   In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form. 
   Many of the methods are described in their most basic form but operations can be added to or deleted from any of the methods and information can be added or subtracted from any of the described messages without departing from the basic scope of the present invention. Any number of variations of the inventive concept is anticipated within the scope and spirit of the present invention. In this regard, the particular illustrated example embodiments are not provided to limit the invention but merely to illustrate it. Thus, the scope of the present invention is not to be determined by the specific examples provided above but only by the plain language of the following claims.