Guided Growth and Electrical Probing of Neurons on Arrays of Biofunctionalized GaAs/InGaAs Semiconductor Microtubes

We demonstrate embedded growth of cortical mouse neurons in dense arrays of semiconductor microtubes (see Figure (a,b)). The microtubes, fabricated from a strained GaAs/InGaAs heterostructure, guide axon growth through them and thus, enable the outgrowth of complex, artificial neuronal networks (see Figure (c)). At the same time, in situ electrical sensing is made possible. We present methods of stimulating and sensing action potentials, where electrodes are embedded inside the microtubes (see Figure d)). The wrapping of these electrodes around the axon greatly increases the contact area, and, with the fabrication of multiple electrodes along the tube length allow for the measurement of action potential propagation along single axons. The coaxial nature of the microtubes - similar to myelin - is expected to enhance the signal transduction along the axon.Our choice of GaAs, an optical III-V semiconductor, offers a variety of advantages over Si despite its toxicity: Its electron velocity and mobility is generally higher than, resulting in lower noise levels of possible electronic devices. We present a technique of suppressing arsenic toxicity and prove its efficiency by the results of neuronal cell culture.View Large Image | View Hi-Res Image | Download PowerPoint Slide