03/26/2026
On Demand drop ejection was introduced in 1973 with the single nozzle piezo driven ink jet technology by Steve Zoltan. Prior to this date, Continuous Ink Jet technology had been improved to print text, numerals, Braille and even topographical maps using hot melt wax and even liquid metal alloys for emblems.
On Demand Ink jets had problems with acoustics. The nozzles were the the same ones from Continuous Ink Jet. Piezo's had been added to CIJ to break the fluid stream into drops before. I think the On Demand Piezo jet was discovered by over driving the piezo's.
Here we are today praising On Demand ink jet and saying a Drop on Demand is good. Inventors have found ways to remove piezo's from the technology. Piezo's have been engineered to try and remove mechanical vibrations from unwanted fluid drop formations. Acoustics was feared when unexpected drop behaviour was seen. Today, only one product uses an improved single nozzle drop on demand technology for high frequency fluid jetting. (This is not low frequency bio printing with single nozzle dispensing)
