Alexander Gumennik
MIT, Formlabs Inc.
Tuesday, April 12, 2016
3:30 pm
Geological Survey Building –
GY-S201, 10th and Walnut Grove
From Macro to Nano …and Back:
Functional Fiber Devices and Systems for Internet of Things
Abstract: Over the last couple of decades nanotechnology has made a tremendous leap both in synthesis
techniques and in functionality of the resulting nanodevices. Yet there is a surprisingly small number of viable
products that take advantage of this tremendous progress. This is due to challenges of integrating the
nanodevices into macroscale matrices in a scalable manner while still keeping each device accessible. These
challenges involve both packaging of nanoscale devices and bridging the gap between the nanoscale device
and the macroscale world we live in.
As one of the possible solutions to this problem, I envision an introduction of a generic set of fabrication tools.
This toolset includes advanced fiber manufacturing, in-fiber nanofabrication and nanosynthesis and additive
manufacturing capabilities. Implementation of this toolbox suggests a pathway towards realization of functional
devices and structures, applicable on a wide range of scales, and contributing to Internet of Things.
At the heart of this approach is the ability to fabricate multimaterial nanostructures within macroscale fibers by
thermal drawing of “preforms”, comprised of a multitude of disparate materials – including metals,
semiconductors, and insulators. The macroscopic preform, which is essentially a scaled up replica of the final
device, is drawn into kilometers of fiber, while maintaining the geometry of its original cross section. Thermal
drawing results in structures with aspect ratios of trillions: while the cross sectional features are nanometric, they
span the entire length of the fiber which is kilometers long. Thus, multimaterial fiber devices, manifesting
nanometric and macroscopic properties simultaneously, are exceptionally promising for nano-to-macro
integration.
Drawing multiple materials in the fiber enables devices that can sense and transduce chemical, optical,
electronic, acoustic, and thermal signals, and can interface to biological tissue, which makes them useful to a
wide range of products applicable in a number of technological and scientific areas, including but not limited to
green energy, bioengineering, and distributed hazard sensing.
In addition, exploring capillary instability in a fiber, we’ve discovered that capillary breakup of multiple-core fibers
allows creating discrete nano devices densely packed into the hosting fiber, while each device is externally
contacted by electrodes spanning the entire fiber length. Made of standard microelectronic materials such as
silicon, germanium, silica, gold and platinum, those fibers manifest enhanced sensitivity and fast response to
optical and electrical signals, creating a platform for data exchange applications as well as for efficient biosynthetic interfacing.
For the future, new horizons in this field could be opened implementing a “recursive manufacturing” approach
where a preform of arbitrarily complex cross section would be fabricated by mean of multimaterial additive
manufacturing, and the fiber resulting from the draw of this preform would be used as a feedstock for additive
manufacturing of structural composites and metamaterials with active functionalities, expanding capabilities of
cyberspace.
Biography: Dr. Alexander Gumennik is a Lead Technical Engineer at Formlabs Inc, a Boston-based startup
company developing a desktop stereolithographic 3D printer, and a research affiliate at MIT. Prior to his
postdoctoral research at MIT in the area of multi-material fiber devices, he has acquired PhD in Applied Physics
and BSc in Physics and Mathematics from the Hebrew University of Jerusalem, Israel. Dr. Gumennik’s interests
include photonic circuits, fiber-based and integrated nano-photonics and nano-devices, fabrics with active
functionalities, distributed and remote environmental sensing, and nano-to-macro integration using additive
manufacturing.