Silica microwires, if they could be manufactured or self-assembled in place, have the potential to operate as tiny optical interconnects, says a team of researchers from Australia and France. By carefully controlling the shape of water droplets with an ultraviolet laser, the researchers have found a way to encourage silica nanoparticles to self-assemble into uniform silica wires.
Unlike optical fiber, silica microwires have no cladding, which means they are able to match the pitch of optical waveguides, creating a smaller structure that is better suited for device interconnection. It also leads to greater confinement of light, which minimizes optical losses.
But before this vision can be achieved, the researchers need to perfect the manufacturing process so that highly uniform wires can self-assemble from nanoparticles suspended in a solution. However, as naturally formed round droplets of water evaporate, the microfluidic currents inside the droplet produce uneven microwires. Canning and his team realized that, by using a patterned substrate to change the shape of the droplet and elongate it ever so slightly, they could change the flow patterns inside the drop to control the way that the nanoparticles assembled.
The researchers anticipate that their technology will allow complete control of nanoparticle self-assembly for a variety of technologies and devices, enabling the integration of microfluidic, electronic, and photonic functionality. But it looks like it will be a number of years before the technique finds its way out of the laboratory and intro mainstream production.
The international team described their novel manufacturing technique and its potential applications in a paper published in the Optical Society’s (OSA) open-access journal Optics Materials Express.
By Pauline Rigby
Press release: Self-Assembling Silica Microwires May Herald New Generation of Integrated Optical Devices
J. Canning et al., Optical Materials Express: Laser tailoring surface interactions, contact angles, drop topologies and the self-assembly of optical microwires