Nanoscale field-effect transistors for minimally invasive, high spatial resolution, and three-dimensional action potential recording

Abstract

This chapter is devoted to the development and application of nanoscale fi eld-effect transistors (FETs) for neural and cardiac activity recording. Compared to optical methods, the electrical recording of action potentials has high signal-to-noise ratio (SNR) and temporal resolution. But the need for electrodes limits its spatial resolution and also poses perturbation on the biological system under investigation. One way to overcome these problems is to develop electrical recording devices with nanometer size and high-density scaling-up ability. Microfabricated metal electrodes can be readily patterned into arrays, but it is hard to decrease the size of these electrodes to nanometer scale because of the necessity to ensure a reasonable impedance value at the electrode/electrolyte interface for suffi cient SNR. Field-effect transistors (FETs), on the other side, can sense the potential of the solution independently on the device/electrolyte interface impedance and hence allow for the miniaturization of the probes to nanometer scale, which is important for minimally invasive, high spatial resolution electrical recording and mapping of neuronal activities, as will be discussed in this chapter.