Abstract: An apparatus and method which print a biomolecular droplet onto a solid substrate using an electric charge concentration effect comprises: a needle shaped electric field forming electrode which is made of a conductive material, is disposed vertically, and comprises an accommodating area and a nozzle formed on a bottom end of the accommodating area; a solid substrate which is electrically grounded, is disposed below the electric field forming electrode, and comprises a moisture thin film and a target surface onto which the biomolecular droplet is discharged from the nozzle of the electric field forming electrode; and an open circuit type voltage applying unit which is electrically connected to the electric field forming electrode, applies a charge to the electric field forming electrode, and causes the biomolecular droplet to be ejected onto the target surface.

Abstract: A laser output control apparatus and method are provided. The laser output control apparatus includes a laser unit including a laser diode and a photo diode having at least one connection structure therebetween; a power controller maintaining power of a laser beam emitted by the laser diode constant in accordance with a feedback voltage applied from the photo diode; and a bias voltage application unit selectively applying a bias voltage to the photo diode according to the connection structure so that the photo diode is biased in a reverse direction. Accordingly, a different bias voltage can be selectively applied to a photo diode according to a connection structure in which a laser diode and the photo diode of a semiconductor laser are connected to each other. Accordingly, it is possible to applicable a semiconductor laser device in office appliance regardless of a connection structure of the semiconductor laser device, thereby allowing versatility of used parts and reducing manufacture costs.