Custom water cooling is the most popular cooling technique for overclockers at HWBOT nowadays. Based on numbers from August and September, 50% of the overclocking results on Haswell-E and 22% of the results on Skylake are with the processor cooled by water cooling. Usually you would build a custom cooling setup from water blocks, pumps, and radiators, but at the Georgia Tech university, that's not good enough.
Georgia Tech graduate student Tom Sarvey is using microfluidic passages cut directly into the backsides of FPGA devices, a few hundred microns away from where the transistors are operating. He achieves 60% lower temperatures compared to air cooling, going from 60°C to 24°C with 20°C liquid. The technology is quite disruptive as the research is believed to be the first example of liquid cooling directly on an operating high-performance CMOS chip.
The cooling research was funded by DARPA’s (Defense Advanced Research Projects Agency) Microsystems Technology Office, through the ICECOOL program. For more information, check out the article at Gatech.edu.