Electroactive Scaffold

Electrospinning offers a versatile way to produce one-dimensional micro- or nanometer mats; however, electrospun fibers are typically collected in a random orientation, which limits their applications. NASA has developed a new apparatus that uses an auxiliary counter electrode to align fibers for control of the fiber distribution during the spinning process. The electrostatic force imposed by the auxiliary electrode creates a converged electric field, which affords control over the distribution of the fibers on the rotating collector surface. The process begins when a pump slowly expels polymer solution through the tip of the spinneret at a set flow rate as a positive charge is applied. The auxiliary electrode, which is negatively charged, is positioned opposite the charged spinneret. The disparity in charges creates an electric field that effectively controls the behavior of the polymer jet as it is expelled from the spinneret; it ultimately controls the distribution of the fibers and mats formed from the polymer solution as it lands on the rotating collection mandrel. A broad range of fiber diameters can be manufactured by modifying various parameters of the process and/or polymer solution. Performance data has confirmed the substantial role that the electric field plays in the significant improvement in fiber alignment and control relative to using the rotating collector alone. Prototypes have been produced, and the repeatability of the process has been confirmed. A patent application has been filed.

Once genes for a desired material type, delivery mode, control method and affinity have been chosen, assembling the genetic components and creating the cell lines can be done with well-established synthetic biology techniques. A 3D microdeposition system is used to make a 3D array of these cells in a precise, microstructure pattern and shape. The engineered cells are suspended in a printable 'ink'. The 3D microdeposition system deposits minute droplets of the cells onto a substrates surface in a designed print pattern. Additional printer passes thicken the material. The cell array is fed nutrients and reagents to activate the engineered genes within the cells to create and deposit the desired molecules. These molecules form the designed new material. If desired, the cells may be removed by flushing. The end product is thus a 3D composite microstructure comprising the novel material. This innovation provides a fast, controlled production of natural, synthetic, and novel biomaterials with minimum resource overhead and reduced pre- and post-processing requirements.

Most magnetic therapy research and resulting devices have centered around pulsed unidirectional bioelectric systems. The technology available here for licensing utilizes a square-wave time-varying electrical current, which generates an electromagnetic field, via a wound coil incorporated into a sleeve and encircles the affected appendage. An external and commercially available time-varying compact electrical generator connects to the wound coil within the sleeve and is powered by a 9-volt battery. Prior industry attempts to use electromagnetic therapy on mammalian tissue have historically applied higher than necessary levels of electromagnetism, typically at 50 gauss or more. Researchers found that by inducing a Fourier-curve, time-varying electromagnetic wave at levels within 0.05 0.5 gauss for a pre-determined time-period, was optimum to achieve successful mammalian tissue regeneration. It is theorized that magnetic fields can alter the flow of positively charged calcium ions that interact with the muscles around small blood vessels causing them to relax. This effect in turn, causes constricted blood vessels to dilate, and dilated blood vessels to constrict. Depending upon the type of injury, enhanced tissue repair may occur through the suppression of inflammation, or the increase in blood flow.

An electroactive device is applied to an external wound site. This method utilizes generated low level electrical stimulation to promote the wound healing process while simultaneously protecting it from infection. The material is fabricated from polyvinylidene fluoride, or PVDF, a thermoplastic fluoropolymer that is highly piezoelectric when poled. The fabrication method of the electroactive material is based on a previous Langley invention of an apparatus that is used to electrospin highly aligned polymer fiber material. A description of the fabrication method can be found in the technology opportunity announcement titled "NASA Langley's Highly Electrospun Fibers and Mats," which is available on NASA Langley's Technology Gateway.

NASA GSFCs EHD pump uses electric fields to move a dielectric fluid coolant in a thermal loop to dissipate heat generated by electrical components with a low power system. The pump has only a few key components and no moving parts, increasing the simplicity and robustness of the system. In addition, the lightweight pump consumes very little power during operation and is modular in nature. The pump design takes a modular approach to the pumping sections by means of an electrically insulating cartridge casing that houses the high voltage and ground electrodes along with spacers that act as both an insulator and flow channel for the dielectric fluid. The external electrical connections are accomplished by means of commercially available pin and jack assemblies that are configurable for a variety of application interfaces. It can be sized to work with small electric components or lab-on-a-chip devices and multiple pumps can be placed in line for pumping greater distances or used as a feeder system for smaller downstream pumps. All this is done as a one-piece construction consolidating an assembly of 21 components over previous iterations.