Scanning station overview

Electrionic Components
Electronically, the scanning station is comprised of three major components: the PC, Lego Mindstorms brick, and the Data Acquisition Module.

PC
The PC controls the operation of the other two components via USB connectivity. The data acquisition module is a small home-brewed potentiostat which is controlled by a microcontroller which itself controlled via a USB connection by LabVIEW software running on the PC. The Lego Mindstorms NXT brick is, internally, a LabView-compatible processor which also interfaces with the computer via USB.

Lego Mindstorms NXT
The Lego Mindstorms NXT brick is responsible for controlling the position of the stepper motors, thereby controlling the angle of the mirrors, and thus the position of the laser spot.

Potentiostat
The potentiostat is primarily responsible for detecting the current flow between the working and counter electrodes, either with or without a biasing voltage applied. The microcontroller on the potentiostat also controls the on/off cycle of the laser, so that it is active for only a short period while collecting current response for each 'pixel' of data.

Laser
The laser is the forward module from a Class IIIa laser pointer, powered by 3v supplied by the potentiostat. The momentary contact switch is permanently switched on through the use of a zip tie (see photo at right ), so that on/off control is determined by the presence or absence of a power source.