channel kinetics, synaptic transmission, single neuron computation, oxygen metabolism, or application of dynamic system theory (LaPlaca et al. 2005). Liquid-based template assembly was used to engineer 3D neural networks from neuron-seeded microcarrier beads. Neural interfaces Neural interfaces are a major element used for studying neural systems and enhancing or replacing neuronal function with engineered devices. Engineers are challenged with developing electrodes that can selectively record from associated electronic circuits to collect information about the nervous system activity and to stimulate specified regions of neural tissue to restore function or sensation of that tissue (Cullen et al. 2011). The materials used for these devices must match the mechanical properties of neural tissue in which they are placed and the damage must be assessed. Neural interfacing involves temporary regeneration of biomaterial scaffolds or chronic electrodes and must manage the body's response to foreign materials. Microelectrode arrays are recent advances that can be used to study neural networks (Cullen & Pfister 2011). Optical neural interfaces involve optical recordings and optogenetics, making certain brain cells sensitive to light in order to modulate their activity. Fiber optics can be implanted in the brain to stimulate or silence targeted neurons using light, as well as record photon activity—a proxy of neural activity— instead of using electrodes. Two-photon excitation microscopy can study living neuronal networks and the communicatory events among neurons. Brain–computer interfaces Brain–computer interfaces seek to directly communicate with human nervous system to monitor and stimulate neural circuits as well as diagnose and treat intrinsic neurological dysfunction. Deep brain stimulation is a significant advance in this field that is especially effective in treating movement disorders such as Parkinson's disease with high frequency stimulation of neural tissue to suppress tremors (Lega et al. 2011). Microsystems Neural microsystems can be developed to interpret and deliver electrical, chemical, magnetic, and optical signals to neural tissue. They can detect variations in membrane potential and measure electrical properties such as spike population, amplitude, or rate by using electrodes, or by assessment of chemical concentrations, fluorescence light intensity, or magnetic field potential. The goal of these systems is to deliver signals that would influence neuronal tissue potential and thus stimulate the brain tissue to evoke a desired response (He 2005). Microelectrode arrays Microelectrode arrays are specific tools used to detect the sharp changes in voltage in the extracellular environments that occur from propagation of an action potential down an axon. Dr. Mark