The efficiency and eco-efficiency of manufacturing

In this paper, we review the efficiency of both manufacturing processes and systems over recent decades and compare nano-materials technologies in this context. To a first approximation, nano-materials processes appear to be about as efficient as semi-conductor processes. That is, their second law efficiencies are of the order 10−5, while conventional processes are of order 10−2. However, many of these processes are early in their development and some opportunities do exist for improvement. At the same time, many aspects of these processes (the need for high purity materials, low yields, and operating conditions far from equilibrium) may make these materials vulnerable to high energy prices.