I. Statement of Problem As processing demands continue to increase in the field of computer science and the computing industry, there is a need to improve the cooling systems for central processing units. These processors consist of transistors which amplify and switch electronic signals within the computer. As these transistors conduct electricity through operation, they generate waste heat. If waste heat is not properly managed then it may affect the processing power of a system, or even damage it permanently. This proposal offers a new way of dealing with waste heat while also generating electricity. II. State of the Art Currently the most common method of cooling central processing units (CPU) is through the use of a fan. The fan draws hot air away from the processor and dissipates it to a safer area. As the processor begins to function at a greater capacity, the fan will pump air away from it at a faster rate. This technique is most common because of its cost-effectiveness and versatility. There is another, less common method available for CPU cooling, and that is with a liquid cooling unit. Liquid cooling units work in a similar convective manner as fans do. They simply pump a source of cool liquid over the processing unit in a tube, allowing the heat to be dissipated from the transistors. This liquid is circulated to a heat sink where it may cool down and then be reused for cooling. III. Proposed Solution A new solution to the problem of CPU cooling involves the merging of a liquid cooling system in conjunction with thermoelectric generators (TEG). The idea is that a thermoelectric generator can convert the excess heat from a CPU into electricity that the computer can store for later use. So the wasted heat from the processors is being converted into something useful while reducing the power demands of the computer and solving the issue of waste heat removal. A schematic configuration of the proposed system is provided below in Figure 1. A copper plate is mounted onto the processing unit in order to create an evenly distributed heat source for the generator; the copper is selected because of its ability to conduct heat well. A TEG is then mounted onto the copper plate and a liquid cooling system, complete with cooling coils, is mounted on the other side of it. The cooling coils will allow for a greater temperature difference across the generator, which will allow for a greater amount of heat to be processed into usable electricity.

Fig. 1 Schematic configuration of TEG on CPU processor This system exploits the traditional liquid cooling process by using the temperature difference of the processor and the liquid to create electricity from a thermoelectric generator. There is no other system like this that is able to recycle heat created from a CPU by converting it into electricity. It is assumed that the liquid cooling unit selected for this system will be powerful enough to remove all of the excess heat created by the CPU that is not converted into electricity by the TEG. If this system were introduced into the industry it could reduce the power consumption of a single computer by 0.5-1 W, assuming that the current TEG technology will be able to meet this demand when introduced into the CPU cooling system. The thermoelectric generator chosen for this system is the TEG1 241-1.0-1.2 from EVERREDTRONIC Ltd. This generator is made from a bismuth telluride semiconductor material (Bi2Te3). Bismuth telluride has been extensively used in the construction of thermoelectric materials and their performance has steadily improved since their discovery according to Goldsmid [1]. IV. Patent Position U.S. Patent US20110225982 A1 details a similar method using a thermoelectric cooler to remove heat from a CPU. This patent is not the same idea being presented in this proposal, since it does not actually generate electricity using the waste heat. Additionally, this patent does not provide a total solution for heat removal, a cooling fan is still required for the system since a thermoelectric cooler cannot remove the heat of the CPU at a fast enough rate. V. Estimated Budget An itemized list of some of the basic parts needed for a seedling demonstration is provided along with a preliminary budget. There are enough materials recorded in this list for multiple prototypes to be created in order to optimize the system. This list is created with the assumption that a lab space will be provided, a machine shop will be provided, and Emerging Material Venture Capital will renegotiate funding when large scale manufacturing becomes of interest. It is also assumed that the thermoelectric material being purchased is able to withstand the maximum temperature reached by the CPU.

Item | Unit Price | No. of Units | Price | Dell Inspiron Smart Desktop (w/ Intel Core 2 Duo 2.2 GHz Processor) | $279.00 | 10 | $2790.00 | TEG1 241-1.0-1.2 | $27.99 | 20 | $559.80 | 1/8 “ Copper Sheet Plate 2”x4” | $15.00 | 40 | $600.00 | DEEPCOOL 240 CPU Liquid Cooler | $89.99 | 10 | $899.90 | 5052 Aluminum block (for machining) 12”x2.5”x1/8” | $16.89 | 100 | $168.90 | 0.5”x10’ Copper Tubing | $1.20 | 20 | $12.00 | 16 Gauge Electric Wiring 100’ | $37.99 | 10 | $379.90 | K-type Thermocouple | $38.00 | 2 | $72.00 | Analog Soldering Station | $94.99 | 1 | $94.99 | OCCT Software | $185.00 | 10 | $185.00 | | | | | Grand Total | | $5762.49 |

VI. Timeline After one year of prototyping this project should be considered for manufacturing. If the system is able to produce 0.75 W of power or more, then it will be ready for manufacturing. If the system produces 0.25-0.75 W of power, then all design possibilities should be considered and the engineer will recommend the best one for further prototyping. If further prototyping is needed, then the prototyping budget should be reconstructed. If the system is not able to produce at least 0.25 W of power, then the project should be discontinued.