An Alternative to Electricity

Electrical Energy is one of the greatest and most profound discoveries of mankind. It has allowed the advancement in all areas of life and sciences. But is there some other form of energy that we are missing? we do a really good job with heat and expansion, converting that into locomotive energy. Mainly by containing and directing its expansion, forcing it to push on mechanical linkage to harvest the energy from the expansion; exactly how an internal combustion engine works in a car. So, is there another for of energy we are just oblivious to, or don't understand well enough to harness?