Electronic Characteristics of Bacteriorhodopsin

To effectively integrate bacteriorhodopsin (bR) with micro electromechanical systems (MEMS) and nano electromechanical systems (NEMS) devices, it is critical to know the electrical properties of the material and to understand how it will affect the functionality of the device. Inductance, capacitance and resistance (LCR) measurements can be used to determine material characteristics, such as permittivity, film thickness, and capacitance. In this paper, LCR measurements of dried films of oriented and unoriented bR with both light-on and light-off conditions are presented. Tests were performed on dried films of bR to determine if there is a relationship between LCR measurements and orientation, light-on/off, frequency, and time. The results indicated that the LCR measurements depended on the thickness and area of the film, but not on the orientation, as with other biological materials such as muscle. However, there was a transient LCR response for both oriented and unoriented bR which depends on light intensity. The possible effect of integrating this material with a single electron transistor (SET) is also briefly discussed.