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RFID-tagged drug capsule lets doctors know when it has been swallowed

Taking medication as and when prescribed is crucial for it to have the desired effect. But nearly half of people with chronic conditions don’t adhere to their medication regimes, a serious problem that leads to preventable deaths, drug resistance and increased healthcare costs. So how can medical professionals ensure that patients are taking their medicine as prescribed?

A team at Massachusetts Institute of Technology (MIT) has come up with a solution: a drug capsule containing an RFID tag that uses radiofrequency (RF) signals to communicate that it has been swallowed, and then bioresorbs into the body.

“Medication non-adherence remains a major cause of preventable morbidity and cost, but existing ingestible tracking systems rely on non-degradable electronics,” explains project leader Giovanni Traverso. “Our motivation was to create a passive, battery-free adherence sensor that confirms ingestion while fully biodegrading, avoiding long-term safety and environmental concerns associated with persistent electronic devices.”

The device – named SAFARI (smart adherence via Faraday cage and resorbable ingestible) – incorporates an RFID tag with a zinc foil RF antenna and an RF chip, as well as the drug payload, inside an ingestible gelatin capsule. The capsule is coated with a mixture of cellulose and molybdenum particles, which blocks the transit of any RF signals.

SAFARI capsules with and without RF-blocking coating
SAFARI capsules Photos of the capsules with (left) and without (right) the RF-blocking coating. (Courtesy: Mehmet Say)

Once swallowed, however, this shielding layer breaks down in the stomach. The RFID tag (which can be preprogrammed with information such as dose metadata, manufacturing details and unique ID) can then be wirelessly queried by an external reader and return a signal from inside the body confirming that the medication has been ingested.

The capsule itself dissolves upon exposure to digestive fluids, releasing the desired medication; the  metal antenna components also dissolve completely in the stomach. The use of biodegradable materials is key as it eliminates the need for device retrieval and minimizes the risk of gastrointestinal (GI) blockage. The tiny (0.16 mm²) RFID chip remains intact and should safely leave the body through the GI tract.

Traverso suggests that the first clinical applications for the SAFARI capsule will likely be high-risk settings in which objective ingestion confirmation is particularly valuable. “[This includes] tuberculosis, HIV, transplant immunosuppression or cardiovascular therapies, where missed doses can have serious clinical consequences,” he tells Physics World.

In vivo demonstration

To assess the degradation of the SAFARI capsule and its components in vitro, Traverso and colleagues placed the capsule into simulated gastric fluid at physiological temperature (37 °C). The RF shielding coating dissolved in 10–20 min, while the capsule and the zinc layer in the RFID tag disintegrated into pieces after one day.

Next, the team endoscopically delivered the SAFARI capsules into the stomachs of sedated pigs, chosen as they have a similar sized GI tract to humans. Once in contact with gastric fluid in the stomach, the capsule coating swelled and then partially dissolved (as seen using endoscopic images), exposing the RFID tag. The researchers found that, in general, the tag and capsule parts disintegrated in the stomach at up to 24 h later.

A panel antenna positioned 10 cm from the animal captured the tag data. Even with the RFID tags immersed in gastric fluid, the external receiver could effectively record signals in the frequency range of 900–925 MHz, with RSSI (received signal strength indicator) values ranging from 65 to 78 dB – demonstrating that the tag could effectively transmit RF signals from inside the stomach.

The researchers conclude that this successful use of SAFARI in swine indicates the potential for translation to clinical research. They note that the device should be safe for human ingestion as its composite materials meet established dietary and biomedical exposure limits, with levels of zinc and molybdenum orders of magnitude below those associated with toxicity.

“We have demonstrated robust performance and safety in large-animal models, which is an important translational milestone,” explains first author Mehmet Girayhan Say. “Before human studies, further work is needed on chronic exposure with characterization of any material accumulation upon repeated dosing, as well as user-centred integration of external readers to support real-world clinical workflows.”

The post RFID-tagged drug capsule lets doctors know when it has been swallowed appeared first on Physics World.

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Taiwan’s Moonshot: why ‘T-Dome’ needs systems engineering, not just a shopping list

Earth observation taken during a night pass over Taiwan by an Expedition 36 crew member on board the International Space Station. Credit: NASA / Karen Nyberg

When President John F. Kennedy stood before Congress in May 1961 and declared that the United States would land a man on the moon before the decade’s end, his purpose was not to invent the space program, but to impose a clear objective, a deadline and the resources to unify these efforts. The success of […]

The post Taiwan’s Moonshot: why ‘T-Dome’ needs systems engineering, not just a shopping list appeared first on SpaceNews.

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Quantum state teleported between quantum dots at telecoms wavelengths

Physicists at the University of Stuttgart, Germany have teleported a quantum state between photons generated by two different semiconductor quantum dot light sources located several metres apart. Though the distance involved in this proof-of-principle “quantum repeater” experiment is small, members of the team describe the feat as a prerequisite for future long-distance quantum communications networks.

“Our result is particularly exciting because such a quantum Internet will encompass these types of distant quantum nodes and will require quantum states that are transmitted among these different nodes,” explains Tim Strobel, a PhD student at Stuttgart’s Institute of Semiconductor Optics and Functional Interfaces (IHFG) and the lead author of a paper describing the research. “It is therefore an important step in showing that remote sources can be effectively interfaced in this way in quantum teleportation experiments.”

In the Stuttgart study, one of the quantum dots generates a single photon while the other produces a pair of photons that are entangled – meaning that the quantum state of one photon is closely linked to the state of the other, no matter how far apart they are. One of the photons in the entangled pair then travels to the other quantum dot and interferes with the photon there. This process produces a superposition that allows the information encapsulated in the single photon to be transferred to the distant “partner” photon from the pair.

Quantum frequency converters

Strobel says the most challenging part of the experiment was making photons from two remote quantum dots interfere with each other. Such interference is only possible if the two particles are indistinguishable, meaning they must be similar in every regard, be it in their temporal shape, spatial shape or wavelength. In contrast, each quantum dot is unique, especially in terms of its spectral properties, and each one emits photons at slightly different wavelengths.

To close the gap, the team used devices called quantum frequency converters to precisely tune the wavelength of the photons and match them spectrally. The researchers also used the converters to shift the original wavelengths of the photons emitted from the quantum dots (around 780 nm) to a wavelength commonly used in telecommunications (1515 nm) without altering the quantum state of the photons. This offers further advantages: “Being at telecommunication wavelengths makes the technology compatible with the existing global optical fibre network, an important step towards real-life applications,” Strobel tells Physics World.

Proof-of-principle experiment

In this work, the quantum dots were separated by an optical fibre just 10 m in length. However, the researchers aim to push this to considerably greater distances in the future. Strobel notes that the Stuttgart study was published in Nature Communications back-to-back with an independent work carried out by researchers led by Rinaldo Trotta of Sapienza University in Rome, Italy. The Rome-based group demonstrated quantum state teleportation across the Sapienza University campus at shorter wavelengths, enabled by the brightness of their quantum-dot source.

“These two papers that we published independently strengthen the measurement outcomes, demonstrating the maturity of quantum dot light sources in this domain,” Strobel says. Semiconducting quantum dots are particularly attractive for this application, he adds, because as well as producing both single and entangled photons on demand, they are also compatible with other semiconductor technologies.

Fundamental research pays off

Simone Luca Portalupi, who leads the quantum optics group at IHFG, notes that “several years of fundamental research and semiconductor technology are converging into these quantum teleportation experiments”. For Peter Michler, who led the study team, the next step is to leverage these advances to bring quantum-dot-based teleportation technology out of a controlled laboratory environment and into the real world.

Strobel points out that there is already some precedent for this, as one of the group’s previous studies showed that they could maintain photon entanglement across a 36-km fibre link deployed across the city of Stuttgart. “The natural next step would be to show that we can teleport the state of a photon across this deployed fibre link,” he says. “Our results will stimulate us to improve each building block of the experiment, from the sample to the setup.”

The post Quantum state teleported between quantum dots at telecoms wavelengths appeared first on Physics World.

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Space sustainability will evolve into a data-driven system

Screenshot from ExoAnalytic’s ExoMaps tool depicting the spread of the debris across the GEO belt over a 14 day period. Credit: ExoAnalytic

If you stayed in a hotel last night, there’s a good chance you saw that familiar placard in the bathroom: “Help save the planet — hang your towel and we won’t wash it.” At a recent panel, I asked the audience how many had seen that sign. Most hands went up. Then I asked them […]

The post Space sustainability will evolve into a data-driven system appeared first on SpaceNews.

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Quantum metrology at NPL: we explore the challenges and opportunities

This episode of the Physics World Weekly podcast features a conversation with Tim Prior and John Devaney of the National Physical Laboratory (NPL), which is the UK’s national metrology institute.

Prior is NPL’s quantum programme manager and Devaney is its quantum standards manager. They talk about NPL’s central role in the recent launch of NMI-Q, which brings together some of the world’s leading national metrology institutes to accelerate the development and adoption of quantum technologies.

Prior and Devaney describe the challenges and opportunities of developing metrology and standards for rapidly evolving technologies including quantum sensors, quantum computing and quantum cryptography. They talk about the importance of NPL’s collaborations with industry and academia and explore the diverse career opportunities for physicists at NPL. Prior and Devaney also talk about their own careers and share their enthusiasm for working in the cutting-edge and fast-paced field of quantum metrology.

This podcast is sponsored by the National Physical Laboratory.

Further reading

Why quantum metrology is the driving force for best practice in quantum standardization

Performance metrics and benchmarks point the way to practical quantum advantage

End note: NPL retains copyright on this article.

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Bringing outsiders into the space fold

Falcon 9 launch

SpaceX’s 2026 IPO plans were an early Christmas present for space investors who were already bullish about the year ahead. The move helps push the industry further into the mainstream investment and public consciousness. It also paves the way for others to go public in a capital-intensive business. Despite ongoing financial uncertainty, demand for sovereign […]

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When allies can’t count on U.S. ISR, commercial space becomes strategic

The global security environment is becoming more volatile, not less. The war in Ukraine grinds on. China is increasingly assertive in the Indo-Pacific. The Middle East remains unstable. North Korea continues to test missiles and challenge regional stability. Together, these dynamics are straining the international system in ways not seen since the early Cold War. […]

The post When allies can’t count on U.S. ISR, commercial space becomes strategic appeared first on SpaceNews.

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Mapping electron phases in nanotube arrays

Carbon nanotube arrays are designed to investigate the behaviour of electrons in low‑dimensional systems. By arranging well‑aligned 1D nanotubes into a 2D film, the researchers create a coupled‑wire structure that allows them to study how electrons move and interact as the system transitions between different dimensionalities. Using a gate electrode positioned on top of the array, the researchers were able to tune both the carrier density (number of electrons and holes in a unit area) and the strength of electron–electron interactions, enabling controlled access to regimes. The nanotubes behave as weakly coupled 1D channels where electrons move along each nanotube, as a 2D Fermi liquid where the electrons can move between nanotubes behaving like a conventional metal, or as a set of quantum‑dot‑like islands showing Coulomb blockade where at low carrier densities sections of the nanotubes become isolated.

The dimensional transitions are set by two key temperatures: T₂D, where electrons begin to hop between neighbouring nanotubes, and T₁D, where the system behaves as a Luttinger liquid which is a 1D state in which electrons cannot easily pass each other and therefore move in a strongly correlated, collective way. Changing the number of holes in the nanotubes changes how strongly the tubes interact with each other. This controls when the system stops acting like separate 1D wires and when strong interactions make parts of the film break up into isolated regions that show Coulomb blockade.

The researchers built a phase diagram by looking at how the conductance changes with temperature and voltage, and by checking how well it follows power‑law behaviour at different energy ranges. This approach allows them to identify the boundaries between Tomonaga–Luttinger liquid, Fermi liquid and Coulomb blockade phases across a wide range of gate voltages and temperatures.

Overall, the work demonstrates a continuous crossover between 2D, 1D and 0D electronic behaviour in a controllable nanotube array. This provides an experimentally accessible platform for studying correlated low‑dimensional physics and offers insights relevant to the development of nanoscale electronic devices and future carbon nanotube technologies.

Read the full article

Dimensionality and correlation effects in coupled carbon nanotube arrays

Xiaosong Deng et al 2025 Rep. Prog. Phys. 88 088001

Do you want to learn more about this topic?

Structural approach to charge density waves in low-dimensional systems: electronic instability and chemical bonding Jean-Paul Pouget and Enric Canadell (2024)

The post Mapping electron phases in nanotube arrays appeared first on Physics World.

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CMS spots hints of a new form of top‑quark matter

The CMS Collaboration investigated in detail events in which a top quark and an anti‑top quark are produced together in high‑energy proton–proton collisions at √s = 13 TeV, using the full 138 fb⁻¹ dataset collected between 2016 and 2018. The top quark is the heaviest fundamental particle and decays almost immediately after being produced in high-energy collisions. As a consequence, the formation of a bound top–antitop state was long considered highly unlikely and had never been observed. The anti-top quark has the same mass and lifetime as the top quark but opposite charges. When a top quark and an anti-top quark are produced together, they form a top-antitop pair (tt̄).

Focusing on events with two charged leptons (top quarks and anti-top quarks decay into two electrons, two muons or one electron and one muon) and multiple jets (sprays of particles associated with top quark decay), the analysis examines the invariant mass of the top–antitop system along with two angular observables that directly probe how the spins of the top and anti‑top quarks are correlated. These measurements allow the team to compare the data with the prediction for the non resonant tt̄ production based on fixed order perturbative quantum chromodynamics (QCD), which is what physicists normally use to calculate how quarks behave according to the standard model of particle physics.

Near the kinematic threshold where the top–antitop pair is produced, CMS observes a significant excess of events relative to the QCD prediction. The number of extra events they see can be translated into a production rate. Using a simplified model based on non‑relativistic QCD, they estimate that this excess corresponds to a cross section of about 8.8 picobarns, with an uncertainty of roughly +1.2/–1.4 picobarns. The pattern of the excess, including its spin‑correlation features, is consistent with the production of a colour singlet pseudoscalar (a top–antitop pair in the 1S₀ state, i.e. the simplest, lowest energy configuration), and therefore with the prediction of non-relativistic QCD near the tt̄ threshold. The statistical significance of the excess exceeds five standard deviations, indicating that the effect is unlikely to be a statistical fluctuation. Researchers want to find a toponium‑like state because it would reveal how the strongest force in nature behaves at the highest energies, test key theories of heavy‑quark physics, and potentially expose new physics beyond the Standard Model.

The researchers emphasise that modelling the tt̄ threshold region is theoretically challenging, and that alternative explanations remain possible. Nonetheless, the result aligns with long‑standing predictions from non‑relativistic QCD that heavy quarks could form short‑lived bound states near threshold. The analysis also showcases spin correlation as an effective means to discover and characterise such effects, which were previously considered to be beyond the reach of experimental capabilities. Starting with the confirmation by the ATLAS Collaboration last July, this observation has sparked and continues to inspire follow-up theoretical follow-up theoretical and experimental works, opening up a new field of study involving bound states of heavy quarks and providing new insight into the behaviour of the strong force at high energies.

Read the full article

Observation of a pseudoscalar excess at the top quark pair production threshold

The CMS Collaboration 2025 Rep. Prog. Phys. 88 087801

Do you want to learn more about this topic?

The sea of quarks and antiquarks in the nucleon D F Geesaman and P E Reimer (2019)

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