A Disposable Inkjet Head Driven by Pulsed Laser

This article describes the development and evaluation of a disposable inkjet head driven by a pulsed laser. Since it has a very simple structure compared to other conventional inkjet heads, it is suitable for disposable devices such as various nano-biodevices for Point of Care Testing (POCT). The driving unit in the inkjet head is merely a piece of metal foil without any electric signal or power line. A laser and optics external to the chip provide the energy to drive the head. Explosive vapor bubbles formed on the metal foil in a microchannel during laser irradiation successfully ejected diluted ink and biopolymer samples in water solution, respectively, from the channel as small droplets through the ejection port. The flight speed of the ejected droplets reached 7.2m/s. The biopolymer samples before and after ejection indicated similar mass spectra, as measured by surface-enhanced laser desorption ionization time of flight mass spectroscopy (SELDI-TOF MS).