In a variety of fields, applications are placing conflicting demands on structural and motion subassemblies. Increasingly, positions must be controlled in more degrees of freedom with higher dynamic and static accuracy, yet faster throughputs and longer travels are necessary to meet financial metrics. Compactness is prized, yet high speeds are demanded. These conflicting requirements have, until recently, had no solution. Application examples abound: 

• Optic assemblies of escalating sophistication require multiple axes of nano-precision alignment, yet they must remain aligned for months of around-the-clock use. 

• Emerging nanoimprint lithographies demand exquisite positioning and trajectory control, yet they must retain alignment integrity under significant physical and thermal stresses. 

• Applications ranging from cell-phone cameras to endoscopy and fluid 
delivery require exceedingly small but stiff and responsive and reliable positioning of optics, probes, shutters and other small loads. 

Fortunately, a confluence of new piezo-based approaches has breathed new capability into the nano- and micro-positioning world. Some of these represent significant incremental advancement of essentially traditional mechanisms; others represent significant forks in the road of positioning technology.