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.
Three companies this week: gas-free air conditioning from Cambridge, soft brain implants from Geneva, and a one-injection gene therapy from Zurich and Geneva.
Let’s dive in.
1. Barocal: air conditioning without the gas
Almost every fridge, air conditioner and data centre chiller on Earth works the same way, using a design that is more than a century old. A refrigerant gas is compressed, releases heat, expands and absorbs it again, round and round.
The gases are the problem. The common ones trap heat hundreds to thousands of times more effectively than carbon dioxide, and every system leaks a little, during use, during servicing and when it is scrapped. Barocal's figures put cooling alone at more than 4 billion tonnes of CO2-equivalent in 2022, and global cooling demand is expected to roughly triple by 2050 as the world warms and data centres multiply. Europe is already phasing these gases down by law, without an obvious replacement for many uses.
Barocal, spun out of the University of Cambridge in 2019, uses solids instead. Certain organic "plastic crystal" materials heat up sharply when squeezed and cool down when the pressure is released. Cycle the pressure and you have a heat pump with no gas in it at all. The effect has been known for a while; the catch has always been materials that were too expensive, too weak, or wore out after too few cycles. Founder Xavier Moya, a Cambridge materials physicist, spent more than fifteen years on that problem before founding the company.
The International Energy Agency has singled out Barocal's second-generation prototype as a milestone in solid-state cooling, and the company won the $1 million TERA-Award in 2025.
Where they are: a $10 million seed round in May, led by World Fund and Breakthrough Energy Discovery with IP Group and Cambridge Enterprise Ventures. The first targets are commercial chillers and data centre cooling, the fastest-growing part of a heating and cooling market worth roughly $450 billion a year, and the company says it is working with large equipment manufacturers to get there.
Worth watching, because it removes the gas entirely rather than swapping it for a slightly less harmful one, and the investor list is as strong as climate hardware gets at seed. The milestone ahead is the one the whole field has chased for decades: a commercial unit that matches today's air conditioners on cost and outlasts them on efficiency, over millions of pressure cycles.
Learn more: barocal.com
2. Neurosoft Bioelectronics: a brain implant as soft as the brain
Brain-computer interfaces have gone from science fiction to clinical trials remarkably fast. The most capable ones work by pushing fine electrodes into brain tissue to listen to individual neurons.
The brain does not like that. It is soft, roughly the consistency of set jelly, and it moves slightly with every heartbeat. A rigid electrode sitting inside it is treated as a foreign body, and over time scar tissue forms around it and gradually muffles the signal. That trade-off, depth of signal against damage and durability, has shaped the whole field.
Neurosoft, an EPFL spin-off based at Geneva's Campus Biotech, goes the other way. Its electrodes sit on the surface of the brain rather than inside it, on a material that stretches and flexes with the tissue. The company says they are up to a thousand times more compliant than other flexible interfaces and can cover up to thirty times more of the cortex than current systems, delivered through a minimally invasive procedure.
The first applications are deliberately medical. One programme is a fully implantable system for severe tinnitus, a condition with few good treatments; another supports epilepsy surgery, where surgeons need detailed maps of brain activity before they operate. The longer ambition is to use the recordings to train an AI model of the human cortex, much as language models are trained on text.
Where they are: a $7.5 million seed round in May, led by Skybound Venture Capital with Protocol Labs, IAG Capital Partners and Connecticut Innovations, bringing total funding past $20 million. The device has been used in ten patients across two clinical studies, at UTHealth Houston and UMC Utrecht, including what the company describes as the first 64-channel stretchable brain interface in a human. It also has a partnership with Science Corp, one of the more prominent US brain interface companies.
One to watch. Ten human implants at seed stage is real progress in a field where most rivals are still in animals, and choosing tinnitus gives it a clear medical need and a clear regulatory route. The milestone ahead is the step from temporary recordings during surgery to a permanent implant approved for sale, which is what this round is funding.
Learn more: neurosoft-bio.com
3. Immitra Bio: gene therapy as a single injection
Sickle cell disease affects around 400,000 people in North America and Europe. In 2023, the first gene-editing cure for it was approved, which should have been the end of the story. By Immitra's count, fewer than 150 patients have received an approved gene therapy for it.
The reason is how the treatment is delivered. A patient's blood stem cells are harvested, sent to a specialised facility and edited outside the body. The patient then receives high-dose chemotherapy to clear out the old bone marrow, before the edited cells are infused back. It takes months, involves a long hospital stay and serious toxicity, and in the US the first approved therapy lists at around $2.2 million. The cure works. Very few people can go through it.
Immitra Bio, spun out of ETH Zurich in 2024, wants to skip all of that and edit the cells where they already are, inside the body, with a single injection. No harvesting, no chemotherapy, no transplant. Its approach is also designed to be mutation-agnostic, so one off-the-shelf drug could treat everyone with a given disease rather than being tailored to individual genetic variants.
The lead candidate, IB-003, targets an inherited anaemia, and the company has four programmes in total: three blood disorders, including sickle cell, and one neurological condition.
Where they are: founded by chief executive Jan Nelis, chief scientific officer Amir Taheri, previously head of gene editing at Vector BioPharma, and ETH professor Jacob Corn, one of the better-known names in CRISPR research. A CHF 2.4 million pre-seed round closed in July, led by Backbone Ventures and co-led by OCCIDENT, with ETH Foundation, Zürcher Kantonalbank and Venture Kick taking part. The team of around five is based in Geneva and is targeting clinical trials in late 2028 or early 2029.
One to watch, carefully. If editing inside the body works as intended, it turns a cure that reaches hundreds into one that could reach hundreds of thousands, which is about as large as a medical opportunity gets. The milestones ahead are the ones every new medicine walks in order: preclinical proof that IB-003 edits the right cells safely, then the move into human trials.
Learn more: immitrabio.com
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See you next Saturday.
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