title: A drop-on-demand ink-jet printer for combinatorial libraries and functionally graded ceramics.
abstract: A printer has been designed and built for the preparation of combinatorial libraries of ceramics and for solid freeforming of functionally graded ceramics with three-dimensionally programmable spatial variation in composition. Several ceramic suspensions (as inks) can be subjected to micromixing behind the nozzle and printed at precise positions. Both mixing and positioning are computer-controlled. The machine consists of an XY table to control the geometry, a set of electromagnetic valves that manage the mixing, a combined electromagnetic valve and sapphire nozzle that form the print head, and a computer that controls the whole system. The mixing valves can eject as little as 1 mg/s ink into the mixing chamber. The printer has been controlled, run, calibrated and tested; the composition and geometry of printed mixtures can be controlled precisely. This method for the controlled mixing of powders facilitates the advance of combinatorial methods within the materials sciences.
authors.affiliation: Department of Materials, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
authors.forename: Mohammad Masoud
authors.initials: MM
authors.lastname: Mohebi
authors.forename: Julian R G
authors.initials: JR
authors.lastname: Evans