Table 3.

Comparison between MEMS and NEMS

Implant	Development status	Advantages	Limitations
Microchip	Human trial	Reservoir-specific trigger Drug versatility Remote control of drug administration	Large size Extremely small drug reservoir Very low loading efficiency Complex technology Requires battery Difficult insertion and removal procedures High fabrication and assembly costs Pulsatile drug release Rigid implant
Replenish MicroPump	Human trial	Refillability Drug versatility The Eye™ programmable doses Human safety evaluated	Requires battery Difficult insertion procedure High manufacturing cost Rigid implant
nDS	Translational research	Zero-order kinetics High loading efficiency Drug and reservoir versatility Scalability Transcutaneous refilling Remote tunable release Systemic or site-specific drug release	High rates of drug delivery (mg/day) require large membrane surface area Difficult insertion and removal procedures Rigid implant
NanoPortal Membrane	Translational research	Drug versatility Zero-order kinetics Small size and optimal shape High loading efficiency	Drug release for 3 months to 1 year Implant must be exchanged Rigid implant
NANOPOR™ technology	Translational research	Zero-order kinetics Prozor™ technology for insoluble drugs Small size and optimal shape High Loading efficiency Low manufacturing cost	Implant must be exchanged Rigid implant