inks as described in the above referenced commonly assigned u s patent application ser no 08 868 426 filed jun 3 1997 in accordance to an embodiment of the present invention an ink pressure controller 90 controls the pressures in ink 20 30 40 and 50 the ink pressures in the ink reservoirs can be controlled by accurately positioning the height of the top ink surfaces in the ink reservoirs alternately the inks can be contained in rubber bladders the ink pressures can be precisely controlled by varying mechanical forces exerted on the rubber bladders one advantage of the present invention is that only static positive pressures are required to be applied to the inks in the reservoirs preferably the ink pressures are not varied during the printing procedure for each print however after a number of prints the ink pressures can be adjusted to maintain the proper static ink pressures required for contact microfluidic printing it is understood that the ink pressure controller 90 shown in fig1 represents only one embodiment of the present invention as described below the present invention does not always require the inks to be pressurized the ink flow can be achieved by capillary action forces in the receiver 100 the ink viscosity in the microfluidic printing device 9 is regulated by heater controller 92 as described below the ink flow can be regulated by electrokinetic pumps 130 the heater controller 92 is an electronic device that sends control signals that controls the power and temporal duration of the heating at the heaters in both the reservoirs 20 30 40 50 and ink supply lines the.