To understand how the brain represents the world is a central theme in neuroscience. Neural circuits encode information in terms of rate, timing and synchrony of action potentials arising from the activity of a complex spatial organization of excitatory/inhibitory neurons. The identity of the active neurons at any given time has a profound effect onto the final outcome and regulates fundamental human psychophysical behavior. Attempts to decode the complex behaviors in neurons has led to development of several neuromodulation and sensing tools, by which neural activity can be controlled by microelectrodes or through genetically altering specific neural circuits, ultimately to deliver electrical impulses. Unfortunately, these techniques introduce strong perturbations to the observed system, without reaching the desired spatio-temporal resolution. Experimental approaches that allow non-invasive activation of specific phenotypic groups of neurons could introduce systematic variation of the timing of signals revealing how neural ensembles encode information. Here we propose a novel (nano)tool to alter membrane potential in specific neuronal phenotypes in a spatiotemporally controlled manner.