EM Modululation
In addition to imparting self-healing or thermal management in synthetic material systems, microvascular networks also provide a means to modulate electromagnetic (EM) properties. By circulating fluids that are conductive or magnetic, a variety of "smart" EM applications are now possible.
Reconfigurable Antennas
Antennas, devices capable of transmitting/receiving electrical signals, are ubiquitous components to modern electronics. However, the increasing saturation of these electronic devices has resulted in the rapid dwindling of available radio frequency (RF) bandwidth. Microfluidically reconfigurable antennas can reconfigure on demand to dynamically utilize either unused or low traffic frequencies. We are exploring the use of conductive fluids (e.g. liquid Ga-In metal) circulated within microvascular substrates to achieve reconfiguration.
Slot antenna design and sample (top images). Standing wave ratio with microchannel empty (bottom left) and filled with liquid Ga-In metal (bottom right).
Electromagnetic Modulation
We are also exploring the use of microvascular technology to modulate the electromagnetic (EM) signal emanating from a structural material. By circulating ferromagnetic fluids throughout the vascular network of a microvascular composite the EM signature can be controlled, shaped, and potentially cloaked.
Artistic rendition of active electromagnetic modulation of an aircraft (top left). A microvascular glass/epoxy composite with embedded sinusoidal microchannels (top right) is used to circulate a ferrofluid and imaged by a magneto-optic microscope showing the non-uniform magnetic flux emanating from the surface of the composite.