  A direct electronics printing technique through atomized spraying for
patterning room temperature liquid metal droplets on desired substrate surfaces
is proposed and experimentally demonstrated for the first time. This method has
generalized purpose and is highly flexible and capable of fabricating
electronic components on any desired target objects, with either flat or rough
surfaces, made of different materials, or different orientations from 1-D to
3-D geometrical configurations. With a pre-designed mask, the liquid metal ink
can be directly deposited on the substrate to form various specific patterns
which lead to the rapid prototyping of electronic devices. Further, extended
printing strategies were also suggested to illustrate the adaptability of the
method such that the natural porous structure can be adopted to offer an
alternative way of making transparent conductive film with an optical
transmittance of 47% and a sheet resistance of 5.167{\Omega}/O. Different from
the former direct writing technology where large surface tension and poor
adhesion between the liquid metal and the substrate often impede the flexible
printing process, the liquid metal here no longer needs to be pre-oxidized to
guarantee its applicability on target substrates. One critical mechanism was
found as that the atomized liquid metal microdroplets can be quickly oxidized
in the air due to its large specific surface area, resulting in a significant
increase of the adhesive capacity and thus firm deposition of the ink to the
substrate. This study established a generalized way for pervasively and
directly printing electronics on various substrates which are expected to be
significant in a wide spectrum of electrical engineering areas.
