Patent attributes
Methods, apparatus, and computer program, for use in fabricating a chemical array. The method may use an apparatus which includes a head system, a transport system, and a processor. The head system has multiple groups of drop dispensers which move in unison, each group having multiple dispensers. The transport system can move the head system with respect to a substrate with different dispensers of the groups following respective paths. The processor can dispense droplets from dispensers during operation of the transport system, in a pattern along a selected path for each group so as to form the array. The method includes identifying an error in one or more dispensers. When a dispenser of a first group is in error, then a second dispenser of each group is moved along the selected path for its group while dispensing droplets from at least the second dispenser of the first group in at least part of the pattern for the selected path of the first group.