MEM/NEM devices for drug delivery :
The field of micro-/nanoelectromechanical (MEM/NEM) device-based drug delivery has also made significant headway over the past decade. In particular, implantable microchips containing nanosized reservoirs have been developed to deliver drugs for long time periods in a precisely controlled manner; microneedles are being tested in painless transdermal drug delivery; and the incorporation of nanofeatures (e.g. nanopores, nanochannels, and nanoparticles) in microfabricated systems are perfecting drug delivery and immunoisolation techniques. Intriguingly, these devices can be further modified to deliver new therapeutics, achieve targeted delivery, and co-deliver multiple agents. Substantial efforts are also being put into creating intelligent devices that could potentially sense when and how much dose is needed and then automatically release it from reservoirs. To do this, one feat that must be met is the continuous and stable monitoring of physical and biochemical conditions, in situ. The recent development of nanotechnology-based sensors (e.g. nanowire and nanotube) may offer new ways to address this concern, and could even facilitate device miniaturization.