Violations of the second law of thermodynamics would be commonplace if it were not for misleading education of this kind:

http://physics.bu.edu/~duffy/py105/Heatengines.html
"A necessary component of a heat engine, then, is that two temperatures are involved. At one stage the system is heated, at another it is cooled."

This is simply not true. There are heat engines functioning in isothermal conditions - e.g. the work-producing force is activated by some chemical agent, not by heating. I have already described macroscopic contractile polymers which, on adding acid (H+) to the system, develop a huge work-producing force, contract and light a weight:

http://www.gsjournal.net/old/valev/val3.gif

All isothermal heat engines, except for those which do not differ essentially from ideal gas systems, can violate the second law of thermodynamics. However, under isothermal conditions, the heat that is to be converted into work is supplied extremely slowly - a major hurdle that prevents not only technological applications but also convincing demonstrations of the violation.