Sonochemical surface modification: A route to lean, green and clean manufacturing?

Traditional surface modifi cation techniques utilize hazardous chemistry, operate at high temperatures and require copious rinsing. Ultrasound has long been a "bolt on" for such processes with little thought to optimizing its driving force - the process of acoustic cavitation. This paper demonstrates that, by understanding the factors affecting acoustic cavitation and the employment of suitable ultrasonic equipment, sonochemical surface modifi cation can be achieved on a range of substrates in solutions as benign as water, therefore reducing process stages, rinsing and operating temperatures. Sonochemical surface modifi cation is therefore lean, green and clean and could potentially lead to more sustainable manufacturing.