Bristol Robotics Laboratory

The Starlink Tables Infrastructure Library Tool Set (STILTS) is a powerful suite for astronomical data analysis, particularly useful when dealing with large datasets. However, like other software suites in astronomy its comprehensive syntax creates a significant learning curve to new users. To address this, we present STILTS-NLI, a natural language interface that generates STILTS commands from user prompts, with agentic support for a user-friendly experience. We developed STILTS-NLI by fine-tuning a compact, open-source Large Language Model (LLM) on a synthetically generated dataset. This dataset was curated and validated to ensure both comprehensive coverage of key STILTS functionalities and the syntactic correctness of the resulting commands. Our results demonstrate that this specialised model generates valid commands that match and in some cases outperform larger proprietary models. By leveraging small, open-source models, STILTS-NLI provides an accessible, low-resource solution that lowers the barrier to entry for using STILTS.

Studying droplet dynamics is crucial for microfluidics, materials science and soft robotics. Electric and magnetic fields enable precise droplet handling for drug delivery and diagnostics, but high-energy inputs trigger droplet instabilities and explosive breakup. Here these materials instabilities are leveraged for high energy transduction in liquid metal droplets with high surface tension and conductivity. Liquid metal shapeshifting (LMSS) is introduced, a method for fluidic power generation that uses Lorentz forces and surface tension. Demonstrated in a low voltage (mean≤0.1V), soft, bidirectional pump, it features a simple design with two electrodes, one liquid metal drop, and a small magnet, which can be driven directly from an AAA battery, outperforming previous pumps. Demonstrating versatility, this shapeshifting approach is applied to create an active wearable photoprotective skin, soft robotic actuators, and adaptive color-changing units for clothing, establishing a range of material-focused applications. The liquid metal shapeshifting system represents a transformative material platform for compact, integrated fluidic power supplies and its potential spans applications across lab-on-a-chip devices, micro/macro robotics, adaptive materials, and wearable technologies, positioning it as a foundational technology for the next generation of multifunctional, fluidic-driven soft machines.

Abstract Black hole-created radio jets frequently interact violently with their host galaxies at z > 2, creating stars. Coma A (3C277.3) is one of few luminous low-redshift radio sources where jet-galaxy interactions deflect the jet and induce star formation - a nearby laboratory of massive galaxy formation. We present the first LOFAR VLBI radio image of Coma A and compare it with VLT/MUSE optical images and Chandra X-ray maps. Remarkable features of the radio emission are clumpiness, multiple filaments and the relation of the radio to the optical and X-ray morphologies. The optical continuum image shows a swarm of galaxies apparently merging with Coma A, similar to high-redshift radio protoclusters. Three optical clumps are probable remnants of a merging galaxy, fragmented by collision with the jet. We suggest that magnetic turbulence in Coma A-type radio-emitting clumps, could trigger radio jets in quiescent black holes and that positive feedback from radio jets could contribute to the structure of the high-redshift cosmic web. A prediction of such a scenario is that the morphologies of high-redshift extended radio sources are oriented preferentially along cosmic web filaments, with important implications for how the first supermassive black holes formed.

We provide direct evidence of two-dimensional hole gas (2DHG) conduction occurring in parallel with the two-dimensional electron gas (2DEG) channel in AlN/GaN/AlN high-electron-mobility transistors, using combined electrical characterization and electric-field-induced second harmonic generation. Anomalous OFF-state leakage and diode-like field distributions, which are also confirmed in isolation structures where the top heterostructures along with the 2DEG channel have been etched, reveal a buried leakage path mediated by the 2DHG. This leakage arises from Fowler–Nordheim tunneling with electron–hole pairs generation under the gate, which activates a vertical 2DEG–2DHG diode-like pathway, and from Poole–Frenkel transport that connects the 2DHG to the ohmic contacts. An equivalent circuit model is proposed to describe these mechanisms. The upper bound of the buried 2DHG sheet resistance is estimated to be 10 MΩ/sq, while the vertical resistance between the 2DHG and n++GaN is 35 MΩ mm. These findings provide a direct visualization and a comprehensive model of 2DHG-mediated leakage, offering design strategies to suppress parasitic conduction and improve device performance.

Multi-Uav systems enable rapid wide-area coverage and monitoring, but mission planning for large fleets over very large areas is complex and slow. In this paper, we present a scalable real-time strategy for large geographical areas that couples centralised partitioning with decentralised planning. The method integrates k-means clustering, Voronoi tessellation, and lawnmower patterns. We demonstrate it on diverse real-world areas, including the largest national parks in the UK and the U.S., Quebec, and Antarctica; and analyse its variability to highlight the algorithm’s flexibility and robustness. Finally, we show the system’s effectiveness and scalability by planning a near-complete coverage of the state of California in 10 h with 40 UAVs cruising at 32 m/s (115 km/h).

ABSTRACT Understanding the cold atomic hydrogen gas (H i) within cosmic filaments has the potential to pin down the relationship between the low density gas in the cosmic web and how the galaxies that lie within it grow using this material. We report the discovery of a cosmic filament using 14 H i-selected galaxies that form a very thin elongated structure of 1.7 Mpc. These galaxies are embedded within a much larger cosmic web filament, traced by optical galaxies, that spans at least $\sim 15$ Mpc. We find that the spin axes of the H i galaxies are significantly more strongly aligned with the cosmic web filament ($\langle \vert \cos \psi \vert \rangle = 0.64 \pm 0.05$) than cosmological simulations predict, with the optically selected galaxies showing alignment to a lesser degree ($\langle \vert \cos \psi \vert \rangle = 0.55 \pm 0.05$). This structure demonstrates that within the cosmic filament, the angular momentum of galaxies is closely connected to the large-scale filamentary structure. We also find strong evidence that the galaxies are orbiting around the spine of the filament, making this one of the largest rotating structures discovered thus far, and from which we can infer that there is transfer of angular momentum from the filament to the individual galaxies. The abundance of H i galaxies along the filament and the low dynamical temperature of the galaxies within the filament indicates that this filament is at an early evolutionary stage where the imprint of cosmic matter flow on galaxies has been preserved over cosmic time.

Nonlinear interferometry has widespread applications in sensing, spectroscopy, and imaging. However, most implementations require highly reflective mirrors and precise optical alignment, drastically reducing their versatility and usability in outdoor applications. This work is based on stimulated parametric downconversion, demonstrating methane absorption spectroscopy in the mid-infrared (MIR) region by detecting near-infrared photons using a silicon-based CMOS camera. The MIR light, used to probe methane, is diffusely backscattered from a Lambertian surface, experiencing significant transmission loss. We implement a single-mode confocal illumination and collection scheme, using a two-lens system to mode-match the interfering beams to achieve background methane detection at a distance of 4.6 m under a 57 dB loss. Our method is also extended to real-world surfaces, such as glass, brushed metal, and a leaf, showing robust background methane sensing with various target materials.