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Metamaterials Blog (with Meta Title)

Metamaterials Blog (with Meta Title)

Below you will find the prognostications I was able to record from an advanced materials venture capitalist whom I know well. I’m afraid that some of the knowledge gained from our dialogues has been lost to antiquity and general forgetfulness, but I have placed what remains here on this digital repository for blogs written by advanced materials venture capitalists:

VCs are often criticized for their propensity to over-hype portfolio companies or specific opportunity areas and then start to believe their own hype. This circular reasoning can at times lead to some spectacularly bad investment decisions. When we take our prior postulations as canonical supporting fact, it’s quite hard to form a persuasive argument. The premise and conclusion are inextricably linked and both require additional evidence to prove convincingly.

Inherently biased self-referential reasoning is obviously a poor way to make investment decisions. However, in the advanced materials world, the idea of ‘self-referential’ aka ‘meta’ takes on quite a different meaning…

Metamaterials are artificially structured materials that usually have properties not found in nature. Their unique properties arise principally from designed periodic structures instead of from their chemical constituents and atomic crystal structure. These repeating patterns occur at length scales much smaller than the wavelengths of the electromagnetic radiation that they influence in interesting ways. Essentially, the created repeating structural features in a metamaterial function analogously to atoms or molecules in conventional materials.

The range of exotic phenomena that metamaterials can exhibit is quite broad. The most publicized phenomenon is negative index of refraction. A material with a negative refractive index is also called a left-handed material; they possess simultaneous negative effective permittivity and permeability across a specific frequency range. The reversal of Snell’s law of refraction is a consequence of this exotic property. That means that when light passes from a normal positive-index material like air, glass, or water to a negative-index metamaterial, the light is refracted on the same side of the normal as the incident light. This is shown in the illustration below:

refraction.png

The ability of metamaterials to influence the propagation of electromagnetic radiation in unique ways has inspired researchers to explore exciting real world applications. One of the most promising near term areas for practical exploitation of metamaterials is in telecommunications. Antennas made from metamaterials can offer improved performance (higher radiated power) at very small sizes. Traditional antennas must be at least half the size of the signal wavelength but metamaterial antennas are not constrained by this conventional rule. On the subject of breaking conventional physical ‘laws’, lenses based on metamaterials have been demonstrated in the lab to provide resolution multiple times better than the conventional diffraction limit, which is dependent on the wavelength of light being focused.

Another interesting application is in the field of transformation optics: the so called “invisibility cloak”. The idea here is that a metamaterial can wrap light around a “cloaked” area without any scattering. This creates a virtual empty space making an object inside the metamaterial cloak seemingly invisible. While Wonder Woman’s Invisible Plane is likely quite far off and there are many more technical hurdles to overcome, a successful demonstration of an invisibility cloak was achieved over 10 years ago at microwave frequencies.

It is possible that metamaterials could also be used in security and medical imaging. For example, research teams are attempting to enable sub-wavelength resolution for MRI scanners using metamaterials. Because metamaterials can be designed for wave manipulation beyond the electromagnetic spectrum including but not limited to acoustic and thermal systems, I am confident that other commercial applications will be explored in the future.

Although Don Quixote is credited as one of the earliest and best examples of metafiction, the titular character is mostly associated with impracticality and being out of touch with the real world. While it’s still early days in metamaterials commercialization, the advanced materials venture capitalist I spoke with thinks metamaterials’ promise in practical applications is more than a quixotic pipe dream. I’m inclined to believe him too as I invented him as a literary device for this blog. Nonetheless, Pangaea excitedly looks forward to evaluating and supporting metamaterials startups that are solving significant pain points in large markets.

Associate, Pangaea Ventures Ltd. Matt holds an MPhil in Micro- & Nanotechnology Enterprise from the University of Cambridge and graduated summa cum laude from the University of Pennsylvania with a BSE in Materials Science & Engineering.View Matthew Cohen's profile on LinkedIn

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