Pulsatile or timed delivery is preferred for biopharmaceuticals such as parathyroid hormone and satiety hormones. The DELOS PUMPTM enables such patterned delivery. The system relies on the induction of electro-osmotic outflow of drug from a small implantable reservoir through the application of tiny electric current across specially designed DELOS PUMPTM membrane. Nanopor membranes fabricated with materials bearing charged surface groups (such as de-protonated-OH groups of silicon oxide) are fitted between a supply reservoir containing drug dissolved in an electrolyte solution and the external electrolyte (such as extracellular fluid). Pumping ensues via electro-osmotic flow when a direct current of the proper polarity is applied across the membrane (emanating between electrodes placed on either side of the membrane). The system is self-contained and useful for drugs which provide benefit when delivered in pulses (such as parathyroid hormone), at programmed intervals (such as fertility hormones, diabetes control agents, anti-obesity hormones), or delivered by external activation (pain medication, antidotes, stimulants, resuscitation agents).