Deep Tech Brief #04

Welcome to this week's issue of Deep Tech Brief.

Every Saturday, we break down deep tech companies building genuinely hard things, in plain language. No jargon, no hype.

This week, three European teams that all hit the same kind of wall: a mature, trusted technology that has quietly stopped improving. Rubber that cannot stop shedding microplastic. Optical amplifiers that refuse to get smaller. Anti-reflection coatings that fall apart on a curved lens. In each case the usual fix (better chemistry, a thinner film, a bigger box) has run out of room, so each company changed the thing underneath instead.

Microplastics now turn up in human blood and at the bottom of the ocean, and one of the biggest sources is not packaging but rubber. As tires and soles abrade, they shed tiny synthetic particles that do not break down. A widely cited 2020 Pew Charitable Trusts analysis put synthetic tire rubber at 78% of ocean microplastics; other estimates are lower, but even at the low end worn rubber ranks among the largest single sources, and the roughly 200-year-old rubber industry has never had an answer for it.

That is the gap KUORI is going after. The Zurich company, founded in March 2022 out of a design school project, makes circular elastomers for the products that rub against the world, like shoe soles and outdoor gear. Its flagship, BIOWA, is a thermoplastic elastomer with up to 74% bio-based content, built partly from food industry by-products like olive pits and walnut shells.

The edge is not that it is bio-based; plenty of materials are. It is what happens to the particles it sheds. KUORI says the microplastics released through abrasion are designed to biodegrade under natural conditions through water and enzyme activity, so it tackles the pollution where rival "sustainable" plastics do not, once they are loose in the soil. The company also says BIOWA can be recycled up to five times, carries a carbon footprint well below conventional EVA and TPU, and runs on standard injection molding and extrusion lines.

Where they are: KUORI has raised around 2.3 million euros to date, by the company's account, backed by the Migros Pioneer Fund, Innosuisse, and EU programs. CTO Arthur Groh was blunt about the real obstacle, and it is not the science. It is price. He described competing with a crude-oil supply chain that has had decades to drive costs to the floor, while a bio-based newcomer relies on pricier inputs and cannot match those prices until it scales, which it cannot do until customers commit. The classic materials catch-22.

Worth watching, because the environmental case is strong and the recyclability real, but the honest risk is the one Groh named: until regulation bites or volumes climb, KUORI needs patient partners willing to pay a premium now for a material that gets cheaper only later.

Learn more: kuori.ch

Every time you prompt an AI model, banks of GPUs talk to each other, and increasingly they do it with light rather than copper. That shift is why the AI-driven optical transceiver and co-packaged optics market, by LightCounting's estimate, jumped from roughly 16.5 billion dollars in 2025 toward 26 billion in 2026, up 60% in a single year.

But there is a bottleneck. Optical signals fade as they travel, so the network is full of amplifiers that boost them back up. The workhorse, the erbium-doped fiber amplifier, has been around for decades, with one catch: it is a bulky, discrete component. As transceivers shrank and moved onto chips, the amplifier stubbornly stayed a separate box, the last piece of the optical chain that had not been miniaturized.

EDWATEC, a 2023 spin-off from Tobias Kippenberg's photonics lab at EPFL in Lausanne, built the amplifier onto the chip. Its approach implants erbium ions into silicon-nitride waveguides to create an erbium-doped waveguide amplifier, or EDWA. The device delivers about 30 decibels of gain, meaning it makes a signal more than a thousand times stronger, on a chip smaller than 5 square millimeters. Co-founder and CTO Amir Youssefi calls it the world's first on-chip optical amplifier. Integrated amplifiers have been chased for years, so the more precise claim is that EDWATEC reached record compactness and performance and made the part manufacturable.

Where they are: by Youssefi's account the company is about three years old, roughly ten people, hiring, and planning a Series A in around six months, targeting millions of units a year. Independently on the record: it won the grand prize at Switzerland's Venture 2026 competition (150,000 francs, from 450 applicants) and earlier took a 100,000-franc Tech Seed loan from the Foundation for Innovation and Technology. Youssefi says the technology is already being tested by industry leaders.

One to watch. The pull and the physics are both real. The risks are the usual component-startup ones: entrenched incumbents like Coherent and Lumentum, two-year product cycles that punish anyone who slips, and whether EDWATEC's integration approach wins the design slots before a rival's does.

Learn more: edwatec.com

Reflection sounds trivial, but in precision optics it is a failure mode. Bare glass bounces back about 4% of the light hitting each surface, which means lost signal, ghost images, and, in high-power lasers, enough stray energy to damage the device. The standard fix, thin-film coatings, works but only over narrow wavelength bands, fails at steep angles and on curved surfaces, and is mechanically fragile. It is a roughly 5.5 billion dollar market leaning on a technology that has largely maxed out.

nanoAR, a spin-off from the Max Planck Institute for Medical Research in Germany, does not add a coating; it restructures the surface itself. Copying the moth's eye, which is covered in microscopic cones that let light in without bouncing it back, the team etches nanostructures directly into glass or polymer. Because the surface shades gradually from air to solid instead of meeting at a hard boundary, the light simply passes through. By the company's figures this pushes reflectance as low as 0.01% and transmittance as high as 99.8%, holds up across wide angles and curved lenses, and survives high-power conditions that defeat conventional coatings.

By comparison, the best multilayer broadband coatings can get reflection below 1%, but mainly at a straight-on angle and over a limited band, and they sit on the surface as a separate, breakable layer. nanoAR's structure is the surface, which is why it keeps working where coatings quit, and the company holds an exclusive license to the underlying Max Planck patents.

Where they are: this is the earliest stage of the three. CEO Dr. Zhaolu Diao (a photonics PhD from EPFL), with CTO Dr. Xiaodi Hong and COO Dr. Klaus Weishaupt, is running the venture on public research funding, including Germany's EXIST research transfer grant, and plans to formally incorporate nanoAR GmbH by the end of 2026. Diao was candid that the two hard problems are building a business-side team and landing a first reference customer.

One to watch, carefully. The numbers are striking and the platform spans camera lenses to industrial lasers, but moth-eye anti-reflection has been studied in labs for over a decade by many groups. The real test is not the physics, it is whether nanoAR can manufacture these nanostructures affordably at scale and prove it with a paying customer before the funding runway matters.

Learn more: nanoar-tech.com

Three teams, three entrenched industries, one shared move: when the incumbent approach hits a physical ceiling, stop polishing it and change what sits underneath. None of them is proven at scale yet, which is exactly why they are worth knowing now.

Know a deep tech company we should break down next? Hit reply and tell us. The best editions come from real tips.

See you next Saturday.