Nanoscience News (<front>)

The miniaturized and portable bio-battery, fabricated by 3-D printing of living hydrogels containing electroactive Shewanella oneidensis MR-1 biofilms, represents a novel class of engineered living energy materials. The electricity generated by this device can be harnessed for nerve stimulation to enable precise control over bioelectrical stimulation and physiological blood pressure signals.

Harnessing engineered living materials for energy application represents a promising avenue to sustainable energy conversion and storage, with bio-batteries emerging as a pivotal direction for sustainable power supply. Whereas, the realization of miniaturized and portable bio-battery orchestrating off-the-shelf devices remains a significant challenge. Here, this work reports the development of a miniaturized and portable bio-battery using living hydrogels containing conductive biofilms encapsulated in an alginate matrix for nerve stimulation. These hydrogels, which can be 3-D printed into customized geometries, retained biologically active characteristics, including electroactivity that facilitates electron generation and the reduction of graphene oxide. By fabricating the living hydrogel into a standard 2032 battery shell with a diameter of 20 mm, this work successfully creates a miniaturized and portable bio-battery with self-charging performance. The device demonstrates remarkable electrochemical performance with a coulombic efficiency of 99.5% and maintains high cell viability exceeding 90% after operation. Notably, the electricity generated by the bio-battery can be harnessed for nerve stimulation to enable precise control over bioelectrical stimulation and physiological blood pressure signals. This study paves the way for the development of novel, compact, and portable bio-energy devices with immense potential for future advancements in sustainable energy technologies.

Development of Marine-Degradable Poly(Ester Amide)s

This cover illustrates the development of high-performance poly(ester amide)s (PEAs) for marine-degradable applications. Combining strength and biodegradability, PEAs promise sustainable solutions for fishing gear, reducing ocean plastic pollution with upcycled, eco-friendly materials. More details can be found in article number 2417266 by Hyeonyeol Jeon, Hyo Jeong Kim, Jeyoung Park, Dongyeop X. Oh, and co-workers.

Spin-Orbit-Locking Holography

In article number 2415142, Xiaocong Yuan, Puxiang Lai, Qinghua Song, and co-workers present a multi-channel vectorial holography technique encoded by both the spin and orbital angular momentum using a minimalist, non-interleaved, geometry-phase metasurface. It not only substantially enhances the selectivity of input light, exhibiting intriguing spin-orbit-locking behavior, but also expands the multiplexing channels of the output optical field, holding great potential for advanced light manipulation.

Mechanical Metamaterial

In article number 2410865, Fei Pan, Yuli Chen, and co-workers propose an automatically on-demand reprogrammable mechanical metamaterial. Driven by the pre-established structure-performance relations, the metamaterial can automatically tune its building blocks' states using built-in actuators to match different target stress-strain curves in real time. This offers a new solution for the physical properties reprogramming of artificial systems.

Pixel Circuit Integrated MicroLED

In article number 2416015, Kyungwook Hwang, Hojin Lee, Geonwook Yoo, and co-workers demonstrate advanced technology that will transform the current display industry beyond the backplane limits. The pixel circuit integrated micro-LED (PIMLED) not only incorporates an active-pixel circuit but is also compatible with the intrinsic randomness of fluidic-based transfer technology, ensuring no angular misalignment. The results bring forward scalable, transparent, and form-factor free active-matrix micro-LED display.

Sapphire Machining Integrated with Superconducting Qubits

In article number 2411780, Connor D. Shelly and co-workers from OQC and the University of Southampton present the integration of machining of sapphire substrates with superconducting qubits and quantum processors. It is shown that this sapphire machining process is compatible with the production of high-coherence qubits whilst maintaining tight Josephson junction parameter spread. This work provides a route to further scaling of quantum processors on sapphire.

Molecular Design

In article number 2414080 by Ziyi Ge, Daobin Yang, and co-workers report that the O-shaped dimeric acceptor, 5-IDT, as a guest component can boost the efficiency of organic solar cells to nearly 20%. Moreover, the root reason for the significantly improved thermal stability of the device is clearly revealed.

Self-Assembled Metal Complexes

In article number 2416122, Yuqi Tang, Quan Li, and co-workers present a comprehensive overview of the self-assembly of various metal complexes into the nanoparticles with different morphologies, the mechanisms of self-assembly, and their applications in biomedical fields such as detection, bioimaging, and antitumor therapy.

Metal complexes are widely used in biomedical research due to their excellent properties. To further overcome the pharmacological limitations of metal complexes, the multifunctional nanomaterials are developed. This review introduces the self-assembly of metal complexes into nanoparticles of various shapes, the mechanism of self-assembly, and their applications in biomedical fields such as detection, imaging, and antitumor therapy.

Cisplatin is widely used in clinical cancer treatment; however, its application is often hindered by severe side effects, particularly inherent or acquired resistance of target cells. To address these challenges, an effective strategy is to modify the metal core of the complex and introduce alternative coordination modes or valence states, leading to the development of a series of metal complexes, such as platinum (IV) prodrugs and cyclometalated complexes. Recent advances in nanotechnology have facilitated the development of multifunctional nanomaterials that can selectively deliver drugs to tumor cells, thereby overcoming the pharmacological limitations of metal-based drugs. This review first explores the self-assembly of metal complexes into spherical, linear, and irregular nanoparticles in the context of biomedical applications. The mechanisms underlying the self-assembly of metal complexes into nanoparticles are subsequently analyzed, followed by a discussion of their applications in biomedical fields, including detection, imaging, and antitumor research.

A rapidly and on-demand reprogrammable mechanical metamaterial with an embedded digital interface to its structure-performance relationships is proposed. For a given stress–strain curve, the optimal state can first be calculated based on pre-established structure-performance relationships. Subsequently, the state of the metamaterial can be changed using integrated soft actuators, enabling accurate and fast performance reprogramming.

The physical reprogrammability of metamaterials provides unprecedented opportunities for tailoring changeable mechanical behaviors. It is envisioned that metamaterials can actively, precisely, and rapidly reprogram their performances through digital interfaces toward varying demands. However, on-demand reprogramming by integration of physical and digital merits still remains less explored. Here, a real-time reprogrammable mechanical metamaterial is reported that is guided by its own structure-performance relations. The metamaterial consists of periodically tessellated bistable building blocks with built-in soft actuators for state switching, exhibiting rich spatial heterogeneity. Guided by the pre-established relations between state sequences and stress–strain curves, the metamaterial can accurately match a target curve by digitally tuning its state within 4 s. The metamaterial can be elastically tensioned and compressed under a strain of 4%, and its modulus tuning ratio reaches >30. Moreover, it also shows highly tunable shearing and bending performances. This work provides a new thought for the physical performance reprogrammability of artificial intelligent systems.

Inspired by the Namib Pachydactylus Rangei , a Power-Free Cooling moisture harvester with Luneburg Lens Array is fabricated using Self-Developed μ-ECM process. The synergy between the surface and interface functions endows the PFCMH with Exceptional Passive sub-Dewpoint Cooling and Efficient Harvesting Performance. Installing every 1 m2 of PFCMH can Yield ≈294.5–490.6 kg per year of water and Save ≈198.7–331.0 kWh per year of electricity.

The development of zero-power moisture-harvesting technology in an unsaturated atmosphere is of great significance for coping with global freshwater scarcity. Here, inspired by Pachydactylus rangei's (Namib sand gecko) ability to evade thermal radiation and harvest moisture, a power-free cooling moisture harvester (PFCMH) is fabricated using the continuous, industrialized micro-extrusion compression molding. A Luneburg lens is introduced in the PFCMH for the first time, endowing it with a high reflectivity of ≈92.9% in 0.3 to the 2.5 µm waveband and emissivity of ≈98.1% in 8–13 µm waveband, which are ≈19.2% and ≈15.4% higher than those of the unstructured radiative cooler, respectively. Consequently, a temperature reduction of ≈6.9 °C is achieved. In addition, the wettability of PFCMH is well regulated, at a contact angle of ≈153° and a rolling angle of ≈42°, enabling its surface to efficiently nucleate and transport water droplets. The synergy between the surface and interface functions endows the PFCMH with exceptional passive sub-dewpoint cooling and efficient harvesting performance. Importantly, every 1 m2 of PFCMH can yield ≈294.5–490.6 kg year−1 of water and save ≈198.7–331.0 kWh year−1 of electricity. The PFCMH offers an environmentally, power-free, and promising solution to freshwater scarcity.

This work presents a general multi-channel vectorial holography technique encoded by both the spin and orbital angular momentum using a minimalist, non-interleaved, geometry-phase metasurface. The approach not only substantially enhances the selectivity of the input light, exhibiting spin-orbit-locking behavior, but also expands the multiplexing capacity of the output optical field, opening new avenues for advanced light manipulation.

Vectorial metasurface holography, allowing for independent control over the amplitude, phase, and polarization distribution of holographic images enabled by metasurfaces, plays a crucial role in the realm of optical display, optical, and quantum communications. However, previous research on vectorial metasurface holography has typically been restricted to single degree of freedom input and single channel output, thereby demonstrating a very limited modulation capacity. This work presents a novel method to achieve multi-channel vectorial metasurface holography by harnessing spin-orbit-locking vortex beams. In each channel, the optical vectorial field is encoded with a pair of total angular momentums (TAMs) featuring two orthogonal spin angular momentums (SAMs) independently locked with arbitrary orbital angular momentums (OAMs). The methodology relies on a modified Gerchberg-Saxton algorithm, enabling the encoding of various TAM channels within a single phase profile. Consequently, a pure geometry-phase metasurface with a non-interleaved approach can be used to support such multi-channel vectorial holography, achieving high selectivity of both SAM and OAM, and offering precise routing and manipulation of complex light channels. The work presents a paradigm shift in the field of holography, offering promising avenues for high-density optical information processing and future photonic device design.

A novel method for fabricating poly(ester amide)s combines the benefits of biodegradable polyesters and strong polyamides. These materials, made from upcycled monomers, form films, and yarns with a tensile strength of 109 MPa, tenacity of 5.0 g de−1, and withstand ironing temperatures. They achieve 92% marine biodegradability in 12 months and have a low environmental impact.

Biodegradable polyesters provide an attractive alternative to non-degradable plastics but often encounter a tradeoff between biodegradability and mechanical properties because esters are rotational and lack hydrogen bonds. Conversely, natural polyamides, i.e., silk exhibit excellent mechanical strength because amides are non-rotational and form hydrogen bonds. Unlike esters, the nitrogen in amides can enhance microbial biodegradation. However, protein engineering exhibits limited productivity, and artificial polyamides, i.e., nylon remain non-degradable due to their hydrophobic nature. Herein, a method is proposed for developing poly(ester amide)s (PEA)s, a polyester and polyamide hybrid, to address prevailing production challenges. These materials are synthesized from upcycled monomers in a 10 L reactor and converted into films and yarns. They achieve a tensile strength of 109 MPa and tenacity of 5.0 g de−1, while withstanding ironing temperatures. They achieve a remarkable 92% marine biodegradability in 12 months, which is rarely attained by current bioplastics, and exhibit low environmental impact in terms of greenhouse gas emissions. While biodegradable polyesters have remained within the performance range of commodity plastics, PEAs fall into the high-performance category, potentially reaching markets that existing biodegradable plastics have not, such as fishing lines and clothing.

Negative swelling of hydrogel is achieved via a paradoxical hydration-induced-dehydration pathway. Chemically crosslinked polymer network generates considerable hydrostatic pressure upon swelling, which forces transformable polymers to self-assemble and collapse. The as-fabricated gels can lose 35% weight underwater and exhibit water-strengthened mechanical properties, enhanced structural responsiveness, underwater repair ability, resistance to deformation, and swelling turn-off effect, which significantly broadened potential applications.

Swelling positively in water is a common behavior of hydrogels, which, however, can lead to reduced mechanical performance and stability. Enabling negative swelling represents a promising way to address those issues but is extremely challenging to realize. Here, real negative swelling hydrogels are successfully prepared for the first time through a unique molecular architecture. Specifically designed interpenetrating transformable-rigid polymer network undergoes self-assembly and collapses upon hydration, which in turn dehydrates itself. This paradoxical hydration-induced-dehydration process brings about revolutionary outcomes. Gels can now lose up to 35% weight underwater and exhibit water-strengthened mechanical properties, enhanced structural responsiveness, underwater repair ability, resistance to deformation, and swelling turn-off effect. Those unique properties allow future material development and applications to be carried out in much broader dimensions.

Behavioural interventions can play a crucial role in promoting more sustainable food choices, but their effectiveness depends on both design and context. In this talk, I will present findings from two large-scale online experiments that test different types of behavioural interventions within the same food-delivery app setting. The first study examines the effectiveness of three distinct approaches—an information intervention, a price incentive, and a choice architecture nudge—in shaping meal choices. The second study investigates when and why these interventions work by exploring the role of decision-making speed in shaping their impact. The results suggest that differences in decision time across contexts may help explain the varying effect sizes observed in previous studies of these nudges. Finally, I will conclude by considering whether consumers actually want to be nudged, drawing on evidence from policy support and consumers’ willingness to pay for these interventions.

• Speaker: Paul Lohmann (University of Cambridge)
• Wednesday 05 March 2025, 15:00-16:00
• Venue: Nick Mackintosh Room, Department of Psychology, Downing Site, Cambridge.
• Series: Social Psychology Seminar Series (SPSS); organiser: Yara Kyrychenko.

Add to your calendar or Include in your list

Ice shelves buttress the grounded ice sheet, restraining its flow into the ocean. Mass loss from these ice shelves occurs primarily through ocean-induced basal melting, with the highest melt rates occurring in regions that host basal channels – elongated, kilometre-wide zones of relatively thin ice. While some models suggest that basal channels could mitigate overall ice shelf melt rates, channels have also been linked to basal and surface crevassing, leaving their cumulative impact on ice-shelf stability uncertain. Due to their relatively small spatial scale and the limitations of previous satellite datasets, our understanding of how channelised melting evolves over time remains limited. In this study, we present a novel approach that uses CryoSat-2 radar altimetry data to calculate ice shelf basal melt rates, demonstrated here as a case study over Pine Island Glacier (PIG) ice shelf. Our method generates monthly Digital Elevation Models (DEMs) and melt maps with a 250 m spatial resolution. The data show that near the grounding line, basal melting preferentially melts a channel’s western flank 50% more than its eastern flank. Additionally, we find that the main channelised geometries on PIG are inherited upstream of the grounding line and play a role in forming ice shelf pinning points. These observations highlight the importance of channels under ice shelves, emphasising the need to investigate them further and consider their impacts on observations and models that do not resolve them.

• Speaker: Katie Lowery, British Antarctic Survey
• Wednesday 12 March 2025, 14:00-15:00
• Venue: BAS Seminar Room 2.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.

Add to your calendar or Include in your list

Stratospheric aerosol injection (SAI) is a proposed method of cooling the planet and reducing the impacts of climate change by adding a layer of small particles to the high atmosphere where they would reflect a fraction of incoming sunlight. While it is likely that SAI could reduce global temperature, it has many serious risks and would not perfectly offset climate change. For SAI to be effective, injection would need to take place in the stratosphere. The height of the transition to the stratosphere decreases with latitude, from around 17km near the equator to 8km near the poles. The required injection height would therefore also decrease for higher latitude injection. In this talk, I will present simulations of SAI in an earth system model, UKESM , which quantify how impacts would vary with the injection location and timing, focusing on low-altitude high-latitude injection strategies. Our results suggest that SAI could meaningfully cool the planet even if limited to using existing large jets and injecting at around 13km altitude, if this injection is in the high latitudes during spring and summer. However, relative to a more optimal deployment with novel aircraft at 20km, this strategy requires three times more sulphur dioxide injection and so would strongly increase some side-effects.

Teams link: https://teams.microsoft.com/l/meetup-join/19%3ameeting_Njk5ZjBhMmUtMmIwMS00YjNkLWE4N2QtOTYwN2EyZGRhMzI5%40thread.v2/0?context=%7b%22Tid%22%3a%2249a50445-bdfa-4b79-ade3-547b4f3986e9%22%2c%22Oid%22%3a%2253b919d9-f8a7-4f56-9bb0-baaf0ba7404d%22%7d

• Speaker: Alistair Duffey PhD Student at University College London, Earth Sciences
• Tuesday 18 March 2025, 11:00-12:00
• Venue: Chemistry Dept, Unilever Lecture Theatre and Zoom.
• Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Dr Megan Brown.

Add to your calendar or Include in your list

Note this seminar has been rescheduled from its original date and will be taking place at 4 pm.

Control theory is fundamental in the design and understanding of many natural and engineered systems, from cars and robots to power networks and bacterial metabolism. It studies dynamical systems—systems whose properties evolve over time—and focuses on how to analyze and control their behavior to achieve desirable outcomes, such as preventing car crashes, maintaining voltage levels, or positioning robots accurately. In this talk, we will explore at a high level how control theory can intersect with the study of natural language. First, we will discuss “Language To Control,” which explores how to integrate established control strategies with language algorithms. The goal is to enable intuitive communication with machines using natural language while ensuring the safety and reliability provided by classical control techniques. Second, we will delve into “Control For Language,” where we treat language production as a dynamical system and apply control theory to enhance our understanding and design of language technologies. This includes both foundational models and post-training methods. The aim of this talk is to demonstrate the potential of control theory as a tool for studying language and to open a discussion about potential future avenues.

• Speaker: Carmen Amo Alonso (Stanford University)
• Wednesday 12 March 2025, 16:00-17:00
• Venue: Zoom link: https://cam-ac-uk.zoom.us/j/4751389294?pwd=Z2ZOSDk0eG1wZldVWG1GVVhrTzFIZz09.
• Series: NLIP Seminar Series; organiser: Suchir Salhan.

Add to your calendar or Include in your list

Abstract not available

• Speaker: Timothy Logvinenko, University of Cardiff
• Wednesday 30 April 2025, 14:15-15:15
• Venue: CMS MR13.
• Series: Algebraic Geometry Seminar; organiser: Mark Gross.

Add to your calendar or Include in your list