A closed loop power control based on receiving a continuous quality feedback is described. At the same time, a time counting unit counts time, and before reaching a predetermined time, a display unit is lighted to notify a quick restart period. The droplet operations may in some cases be electrode-mediated. The filler may be present in the polymeric matrix in an amount determined by a property of one or both of the polymeric matrix or the filler. Third, a nano-pattern is formed on the photoresist film by nano-imprint lithography.