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Abstract Inkjet printing has emerged as a versatile technique for the fabrication of functional materials towards non-traditional electronics, offering high precision maskless fabrication capability, low material waste, and wide substrate compatibility. However, the realization of high-quality printing of microscale features requires precise control over the jetting behavior and film formation. In this work, we systematically investigate the printing parameters for the PEDOT:PSS ink on the flexible substrates used in wearable and flexible electronics. By exploring the interplay between the printing waveform parameters, such as drive voltage, dwell time, and jetting frequency, we establish a robust operational window enabling stable droplet ejection and tunable deposition. Droplet spacing is further studied to achieve reliable droplet coalescence for high quality fabrication of the continuous patterns with high line resolution and pattern uniformity. Multilayer printing reveals consistent improvements in film thickness and electrical conductivity, with a pronounced enhancement in early layers due to percolation and phase rearrangement. The achieved printing strategy is successfully applied in functional circuit demonstrations, showing excellent electrical stability under mechanical deformation. This work offers a reproducible and scalable printing approach tailored to the PEDOT:PSS inks, providing a technical foundation for the fabrication of high-performance flexible and printed electronics. 

Abstract Organic electrochemical transistors (OECTs) are gaining significant attention due to their high sensitivity, customizability, ease of integration, and low‐cost manufacturing. In this paper, we design and develop a flexible dual‐gate OECT based on laser‐scribed graphene (LSG) with modified OECT gates for the detection of dopamine and glutamate, two critical neurotransmitters (NTs). The developed OECTs are fully carbon‐based and environmentally friendly. By modifying the gates of OECTs with biopolymer chitosan and L‐Glutamate oxidase enzyme, highly selective and sensitive measurements are successfully achieved with detection limits of 5 nmfor dopamine and 1 µmfor glutamate, respectively. The modified dual‐gate shows no interference between the detections of two neurotransmitters, making it a promising tool for customized multi‐neurotransmitter analysis. The results demonstrate the potential of LSG‐based OECTs in customizable biosensing applications, offering a flexible, cost‐effective platform for biomedical disorder diagnostics. 

Abstract The additional work of ploughing makes seamounts more resistant to subduction and more strongly coupled than smoother areas. Nevertheless, the idea that subducted seamounts are weakly coupled and slip aseismically has become dominant in the last decade. This idea is primarily based on the claim that a seamount being subducted in the southern Japan Trench behaves this way. The key element in this assertion is that largeM ∼ 7 earthquakes that abut the leading edge of the seamount require that the seamount be aseismically sliding to initiate them. More recent observations show instead that the surrounding region is aseismically sliding while the seamount acts as a stationary buttress. Here we re‐examine this case and model it with both weak and strong asperity assumptions. Our modeling results show that only a strong asperity model can produce this type of earthquake. Strong asperities also rupture the seamount in great earthquakes with long recurrence times. This provides the previously unknown source for a series of great tsunami earthquakes that have occurred along the southern Japan Trench, the most recent being the 1677 M8.3–8.6 Enpo Boso‐oki tsunami earthquake. The “weak asperity” hypothesis is thus found to be false in this foundational example. 

Abstract High‐quality‐factor microring resonators are highly desirable in many applications. Fabricating a microring resonator typically requires delicate instruments to ensure a smooth side wall of waveguides and 100‐nm critical feature size in the coupling region. In this work, a new method “damascene soft nanoimprinting lithography” is demonstrated that can create high‐fidelity waveguide by simply backfilling an imprinted cladding template with a high refractive index polymer core. This method can easily realize high Q‐factor polymer microring resonators (e.g., ≈5 × 10⁵around 770 nm wavelength) without the use of any expensive instruments and can be conducted in a normal lab environment. The high Q‐factors can be attributed to the residual layer‐free feature and controllable meniscus cross‐section profile of the filled polymer core. Furthermore, the new method is compatible with different polymers, yields low fabrication defects, enables new functionalities, and allows flexible substrate. These benefits can broaden the applicability of the fabricated microring resonator. 

Abstract The Gravitational-Wave Transient Catalog (GWTC) is a collection of short-duration (transient) gravitational-wave signals identified by the LIGO–Virgo–KAGRA Collaboration in gravitational-wave data produced by the eponymous detectors. The catalog provides information about the identified candidates, such as the arrival time and amplitude of the signal and properties of the signal’s source as inferred from the observational data. GWTC is the data release of this dataset, and version 4.0 extends the catalog to include observations made during the first part of the fourth LIGO–Virgo–KAGRA observing run up until 2024 January 31. This Letter marks an introduction to a collection of articles related to this version of the catalog, GWTC-4.0. The collection of articles accompanying the catalog provides documentation of the methods used to analyze the data, summaries of the catalog of events, observational measurements drawn from the population, and detailed discussions of selected candidates. 

Abstract We report the observation of gravitational waves from two binary black hole coalescences during the fourth observing run of the LIGO–Virgo–KAGRA detector network, GW241011 and GW241110. The sources of these two signals are characterized by rapid and precisely measured primary spins, nonnegligible spin–orbit misalignment, and unequal mass ratios between their constituent black holes. These properties are characteristic of binaries in which the more massive object was itself formed from a previous binary black hole merger and suggest that the sources of GW241011 and GW241110 may have formed in dense stellar environments in which repeated mergers can take place. As the third-loudest gravitational-wave event published to date, with a median network signal-to-noise ratio of 36.0, GW241011 furthermore yields stringent constraints on the Kerr nature of black holes, the multipolar structure of gravitational-wave generation, and the existence of ultralight bosons within the mass range 10⁻¹³–10⁻¹²eV. 

Abstract On 2023 November 23, the two LIGO observatories both detected GW231123, a gravitational-wave signal consistent with the merger of two black holes with masses $137_{-18}^{+23}{M}_{\odot }$and $101_{-50}^{+22}{M}_{\odot }$(90% credible intervals), at a luminosity distance of 0.7–4.1 Gpc, a redshift of $0.40_{-0.25}^{+0.27}$, and with a network signal-to-noise ratio of ∼20.7. Both black holes exhibit high spins— $0.90_{-0.19}^{+0.10}$and $0.80_{-0.52}^{+0.20}$, respectively. A massive black hole remnant is supported by an independent ringdown analysis. Some properties of GW231123 are subject to large systematic uncertainties, as indicated by differences in the inferred parameters between signal models. The primary black hole lies within or above the theorized mass gap where black holes between 60–130M_⊙should be rare, due to pair-instability mechanisms, while the secondary spans the gap. The observation of GW231123 therefore suggests the formation of black holes from channels beyond standard stellar collapse and that intermediate-mass black holes of mass ∼200M_⊙form through gravitational-wave-driven mergers. 

The gravitational-wave signal GW250114 was observed by the two LIGO detectors with a network matched-filter signal-to-noise ratio of 80. The signal was emitted by the coalescence of two black holes with near-equal masses $m_1={33.6}_{-0.8}^{+1.2}{M}_{\odot }$and $m_2={32.2}_{-1.3}^{+0.8}{M}_{\odot }$, and small spins ${\chi }_{1,2}\le 0.26$(90% credibility) and negligible eccentricity $e\le 0.03$. Postmerger data excluding the peak region are consistent with the dominant quadrupolar $(\ell =|m|=2)$mode of a Kerr black hole and its first overtone. We constrain the modes’ frequencies to $\pm 30\%$of the Kerr spectrum, providing a test of the remnant’s Kerr nature. We also examine Hawking’s area law, also known as the second law of black hole mechanics, which states that the total area of the black hole event horizons cannot decrease with time. A range of analyses that exclude up to five of the strongest merger cycles confirm that the remnant area is larger than the sum of the initial areas to high credibility.