Author Archives: Antoine

EUV lithography makes headlines

EUV lithography is now part of everything – including the chips in your iPhone 12 and beyond. I don’t know if it’s because of the chip shortage, the $50B investment of the US government in semiconductor manufacturing, or the realization that having a nearly monopolistic market with its biggest player in Taiwan, at the mercy of an invasion, but there’s a lot of press on EUV lithography right now (I’ve been talking about my work on the topic at Berkeley Lab here: SHARP and MET5, and shared some thoughts on Moore’s law here.)

Me at the inaugural Berkeley Lab Slam (2016), talking about EUV lithography

Here’s a few pieces:

In this story, ASML is the quiet powerhouse – they have a de facto monopoly (their stock rose 10x over the last 5 years) and they keep expanding (ASML opens new state-of-the-art R&D facility in Silicon Valley.) There’s been some hardball played here, with the US pressuring the European company not to sell their technology with China (Reuters), as if it made any sense.

Besides, I am stoked to see my former colleagues from the Center for X-Ray Optics receive recognition for their work!

I hope we’ll get to develop new techniques with x-rays using diffraction-limited beams to further the advances in semiconductors and microchips – skyrmions, superconductivity, memristors, and so many other cool things!

power spectral density of an EUV coherent beam reflected on a naturally rough surface going through an objective zoneplate with a topological charge of 1


I recently read the amazing book “New Expressions in Origami Art” by Meher McArthur, that I found at the shop Paper Tree in the Japan Town of San Fransisco (it’s one of my favorite shops; they always have stunning origami on display, some for sale, from many origamists featured in the book.)

Every page of the book is a delight, where a modern twists (abstraction, wet folding, tessellation) on origami always bring something very fresh.

One Crease, by Paul Jackson

While reading the book and learning about Goran Konjevod (who seems to be a colleague from Lawrence Livermore National Laboratory), I stumbled on the work of Amanda Ghassaei, who has created the Origami Simulator and many other cool simulation tools producing mesmerizing results.

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Plans for the roaring 20’s

I was recently featured twice by Berkeley Lab, first about my work on ALS-U:
Berkeley Lab The Next 90 – Accelerators: Conversation with Antoine Wojdyla.

It was a nice occasion to pay tribute to my grandpa and my grandmother, who passed away last month, and give some representation to the people from the Caribbean. And also explain what I do, and what I’m dreaming up.

Incidentally, I had to clear out my grandparents house, and set foot in his shop, where he was cutting glass and carving wood. In a way, that’s what I am doing right now, studying mirrors and carving out matter, albeit with tighter tolerances.

My grandpa’s shop stockroom (August 2021)

I also had an occasion to share with my colleague Alisa our vision for the Global ERG, which is an association at Berkeley Lab whose goal is to help out international colleagues – many of those who joined lately barely had a chance to meet anyone.
Berkeley Lab The Next 90 – Global ERG: Conversation with Antoine Wojdyla and Alisa Bettale

The scourge of sargassum

I am currently on the island of Saint-Martin, in the French West Indies, about 200 miles away from Puerto Rico, because I couldn’t fly back directly from France, which is still under a Travel Ban order from the US. I have two spend at least two weeks so that I can fly back to Berkeley.

Saint Martin on the map

Walking on beach, it is sad to discover that is littered with sargassum, an invasive algae that barely existed when I was walking my dogs on the beach many years ago. This infestation is quite recent in fact, and somehow started in 2011 (see the excellent piece in The Atlantic by pre-Pulitzer Ed Yong: Why waves of seaweed have been smothering Caribbean beaches.)

Sargassum on Orient Bay, fresh and old (September 2021)

It appears that the bloom may come from the increase in nutrients carried by the Amazon river and making it to the ocean (The great Atlantic Sargassum belt.) Apparently, the problem is becoming more and more acute, and I’ve recently learned that researchers (like my colleagues at Berkeley Lab Lydia Rachbauer) are trying to find enzymes in fish that can actually digest these algae.

Because these algae float in the water, they are effectively a a mix of large floating solar panels, and a potentially a great resource of biofuels, where nothing is needed, since the nutrients are provided for free by farmers from the Amazon river. Apparently, there are companies such as C-combinator who are trying to extract the energy from these algae. I can’t really judge if the economics makes sense (harvesting the algae might be complicated, though they seem very easily visible on satellite images so that might help), but developing adequate techniques for a problem that may blow up seems a good idea.

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My father is a painter, and I really enjoyed one of his last series of paintings.

Here’s his instagram (@romain.wojdyla) and some of his work:

More pictures: Continue reading

Welcome to Gattaca

The movie Gattaca is my favorite movie of all times. It is the story of a person born of natural ways that need to live in a society where everyone has been selected based on their genes. I think it is an absolute masterpiece, with an incredible photography, excellent actors and a very clever script, touching on very deep issues.

I got a chance to visit the place where the movie was filmed, which happens to be the Marin County Civic Center, in San Rafael, 20 minutes North of San Francisco. The place is absolutely wild.

Marin County Civic Center (botanical garden)

While it seems to be a dystopian intrigue around genetic discrimination, it is actually subtle parable for systemic racism. The movie as a whole is a discussion around the fuzzy notion of meritocracy: people are still supposedly selected on their abilities, and it is formally illegal to conduct genetic testing (extending the notion of “protected characteristics”), but this eventually is a sham. It is interesting to notice that the movie has only two black characters – the geneticist (Blair Underwood) and the interviewer (Clarence Graham) – both serving as gatekeepers, closing the door to applicants who would try to escape their condition.

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Connected papers

I’ve discovered Connected Papers and I think it’s awesome!

It’s a tool to see the connection between papers, and therefor ideal to get started in a new field or make sure you’re not missing out on some papers when you’re writing a review!


Paper connectivity map made wit Connected Papers

I’m glad to see new tools helping the conduct of science.

Bibliography management is always flaky, even if we have better tools now such as Mendeley, and overall gathering information and getting in touch with specific scientist is still pretty bad (Researchgate is not very good.) There are some interesting aspects to ORCID, though it doesn’t have the adoption levels it should have to be very useful, and AMiner provides interesting information (sorting researchers’ work by fields) but it doesn’t work flawlessly.

Hikes in Berkeley and around

Some times ago I gave a talk to the Berkeley Lab Postdoc Association about the many hikes around Berkeley.

The slides are available here:

And the recording is here:

Other resources on this blog:

Zoom and defocus

I found working during a pandemic particularly hard. While there are some people who seem perfectly fine with working remotely, it seems that the unease might have to do both with the kind of person you are (introvert/extrovert), but most fundamentally with the nature of your work.

When you work in a team, say in scientific engineering, it seems the biggest challenge with online meetings is the lack of multi-channel conversation and feedback, because it allows to more precisely frame the scope of the task:

Asking the right questions is more important than answering them
– Cantor

… to which Benoit Mandelbrot replied “Asking the right questions is as important as answering them.” This is important, because in absence of a well defined scope, it may take much longer to answer a question (a design, a calculation) than you may think, because the task is ill-posed and you can’t reorient the scope (e.g. refine, modify assumptions) to find a solution in due time.

The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
– Bertrand Russell

I’ve learned from a friend that while Amazon initially said at the start of the pandemic that they would be considering more working from options, they now want to bring everyone to office. It is my impression (at least my experience!) that the initial gains in productivity that made them seriously considering WFH might have come from some initial momentum, where tasks were well-delineated, but eventually faded away.

It is possible that zoom fatigue is also at play, or simply the effect of isolation on people, but I believe that the general exhaustion may also come from a general lack of direction.

edit June 11, 2021: here’s a interesting article from Gibbs at a. at UChicago:
Work from Home & Productivity: Evidence from Personnel & Analytics Data on IT Professionals

Those who did perceive declines in productivity also experienced lower levels of well-being from WFH. Bellmann and Hubler (2020) find that working remotely has no long-run effect on work-life balance, and that a switch to WFH increases job satisfaction only temporarily. Work-life balance mayalso be affected by decreased commuting time. Barrero et al. (2020) estimate that during the height of the pandemic, WFH reduced total commuting time among US workers by more than 60 million hours per work day.


The upgrade of the Advanced Light Source (ALS-U), the project I’m working on, has received CD-2 approval from the US Department of Energy, meaning that we are gearing up towards final design and will soon start ordering tons of magnets and mirrors, and transform our beloved light source into a laser-like source of x-rays, to enable the next generation in batteries, solar cells, computers and medicines (among many other things:)

Advanced Light Source Upgrade Project Achieves Major Milestone

Here’s a few recent highlights from the research enabled by the little synchrotron that could:

Jennifer Doudna, chair of the Advanced Light Source Users’ Executive Committee (around 2001)

A last bit of research by my colleague Alex Frañó (and friend from the ALS Users’ Executive Committee) gets my neurons randomly firing up at night: Rethinking the fundamental way electrons interact in superconducting quantum materials. It progressively appear that skyrmions and superconductivity may be intimately related: A New Twist Reveals Superconductivity’s Secrets (Quanta magazine.) If this is true, we’re on the verge of a major shift: we could potentially engineer interfaces to create room temperature superconductivity. That would be a revolution: we could transfer power from a place to another with no loss (electrical line losses are about 50%) and we could democratize magnetic levitation for transportation.