When the undoped material is sprayed into preformed vias, waveguides solidify. Doping with molecules that recognize specific conditions builds instant sensor arrays. During evaporation, those molecules form spherical cavities called pores. By spraying the material in a line on a silicon substrate, the pores spontaneously line up to form a tiny waveguide of any length and just 25 angstroms in diameter.
Mild heating causes the pores to meld into a solid, permanent structure.
So far, Brinker's team has focused on fluids and gases that lead to existing sensor chips, such as for handheld chemical analyzers. But with the addition of ligands that exhibit molecular recognition, such as molecules that change color in response to the environment, spray-on sensor arrays can be produced. Ligands exist that exhibit molecular recognition for a variety of spray-on sensor types, such as for light, heat, magnetic fields, electric fields, specific gases and specific liquids. Microelectronic future For the future, however, Brinker's team will concentrate on microelectronic devices that can spray directly onto flexible silicon sheets. Eventually, the team envisions spraying whole computer displays onto a flexible silicon sheet from a standard ink-jet printer using color composition software to mix the materials as appropriate for different parts of the circuitry.