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Functional thin coatings are crucial in modern and emerging technologies, providing specified surface properties and protection, thereby influencing the performance and lifetime of materials and devices. The electrodeposition of polymer networks (EPoN) has recently been reported as a facile and potentially broadly applicable method to fabricate conformal polymeric ultrathin films on conductive substrates with arbitrary shapes and surface topography under mild solution conditions. In this work, a new generation of EPoN is introduced that utilizes a chemically reactive polymer appended by a small fraction of a electrochemical crosslinker as side groups. This EPoN iteration eliminates the need for precise end-group functionalization, enables the tuning of crosslink density and film thickness independent of polymer size, and the resulting reactive ultrathin films are amenable to post-deposition modification with desired functionalities using facile click-chemistry. To demonstrate this concept, we electrodeposit polyisoprene with small side-group fractions of the oxidative crosslinker phenol (<5%) as a thiol–ene-reactive polymer-network coating. The EPoN-derived ultrathin films are tunable and uniform with a thickness in the 100s of nanometers depending on phenol fraction and electrodeposition potential, and show a conformal morphology on complex porous electrode architectures. We further demonstrate post-EPoN functionalization of the ultrathin polyisoprene coatings with thiol–ene chemistry. 

Advances in precision coatings are critical in enhancing the functionality of porous materials and the performance of three-dimensionally (3-D) micro-architected devices in applications ranging from molecular sorption and separation to energy storage and conversion. To address this need, we report the cathodic electrodeposition of polymer networks (EPoN) that utilizes the coupling between pre-synthesized polymers with electrochemically active end groups and a complementary crosslinker to form a step-growth polymer network. The electrochemically mediated crosslinking reaction confines the network formation to the electrode surface in a passivating and self-limiting film growth, preventing uncontrolled precipitation and deposition away from the surface. The cathodic electrodeposition is compatible with a variety of conductive substrates, which is demonstrated for 3-D carbons and metals with micron-scale pores of high aspect ratio. The entire pore surface of the 3-D electrodes is enveloped by a conformal polymer thin film that is free of detectable defects and highly electronically insulating for its potential use as an ultrathin artificial electrolyte interphase or solid polymer electrolyte. Since our EPoN concept decouples the polymer functionality from its electrodeposition chemistry, we envision it to be a widely applicable method to coat various conductive non-planar and micro-architected 3-D substrates with polymers of broad functionalities. 

We introduce the polymer analysis and discovery array (PANDA), an automated system for high-throughput electrodeposition and functional characterization of polymer films. The PANDA is a custom, modular, and low-cost system based on a CNC gantry that we have modified to include a syringe pump, potentiostat, and camera with a telecentric lens. This system can perform fluid handling, electrochemistry, and transmission optical measurements on samples in custom 96-well plates that feature transparent and conducting bottoms. We begin by validating this platform through a series of control fluid handling and electrochemistry experiments to quantify the repeatability, lack of cross-contamination, and accuracy of the system. As a proof-of-concept experimental campaign to study the functional properties of a model polymer film, we optimize the electrochromic switching of electrodeposited poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films. In particular, we explore the monomer concentration, deposition time, and deposition voltage using an array of experiments selected by Latin hypercube sampling. Subsequently, we run an active learning campaign based upon Bayesian optimization to find the processing conditions that lead to the highest electrochromic switching of PEDOT:PSS. This self-driving lab integrates optical and electrochemical characterization to constitute a novel, automated approach for studying functional polymer films. 

The existence of a quantum critical point (QCP) and fluctuations around it are believed to be important for understanding the phase diagram in unconventional superconductors such as cuprates, iron pnictides, and heavy fermion superconductors. However, the QCP is usually buried deep within the superconducting dome and is difficult to investigate. The connection between quantum critical fluctuations and superconductivity remains an outstanding problem in condensed matter. Here combining both electrical transport and Nernst experiments, we explicitly demonstrate the onset of superconductivity at an unconventional QCP in gate-tuned monolayer tungsten ditelluride $\left({\mathrm{WTe}}_2\right)$, with features incompatible with the conventional Bardeen-Cooper-Schrieffer scenario. The results lead to a superconducting phase diagram that is distinguished from other known superconductors. Two distinct gate-tuned quantum phase transitions are observed at the ends of the superconducting dome. We find that quantum fluctuations around the QCP of the underdoped regime are essential for understanding how the monolayer superconductivity is established. The unconventional phase diagram we report here illustrates a previously unknown relation between superconductivity and QCP. Published by the American Physical Society2025 

Introducing superconductivity in topological materials can lead to innovative electronic phases and device functionalities. Here, we present a unique strategy for quantum engineering of superconducting junctions in moiré materials through direct, on-chip, and fully encapsulated 2D crystal growth. We achieve robust and designable superconductivity in Pd-metalized twisted bilayer molybdenum ditelluride (MoTe₂) and observe anomalous superconducting effects in high-quality junctions across ~20 moiré cells. Unexpectedly, the junction develops enhanced, instead of weakened, superconducting behaviors, exhibiting fluctuations to a higher critical magnetic field compared to its adjacent Pd₇MoTe₂superconductor. In addition, the critical current further exhibits a notable V-shaped minimum at zero magnetic field. These features are unexpected in conventional Josephson junctions and absent in junctions of natural bilayer MoTe₂created using the same approach. We discuss implications of these observations, including the possible formation of mixed even- and odd-parity superconductivity at the moiré junctions. Our results also demonstrate a pathway to engineer and investigate superconductivity in fractional Chern insulators. 

Two-dimensional (2D) transition metal dichalcogenides (TMDs) is a versatile class of quantum materials of interest to various fields including, e.g., nanoelectronics, optical devices, and topological and correlated quantum matter. Tailoring the electronic properties of TMDs is essential to their applications in many directions. Here, we report that a highly controllable and uniform on-chip 2D metallization process converts a class of atomically thin TMDs into robust superconductors, a property belonging to none of the starting materials. As examples, we demonstrate the introduction of superconductivity into a class of 2D air-sensitive topological TMDs, including monolayers of ${\mathrm{T}}_{\mathrm{d}}\text{−}{\mathrm{WTe}}_2$, $1{\mathrm{T}}^{\prime }\text{−}{\mathrm{MoTe}}_2$, and $2\mathrm{H}\text{−}{\mathrm{MoTe}}_2$, as well as their natural and twisted bilayers, metallized with an ultrathin layer of palladium. This class of TMDs is known to exhibit intriguing topological phases ranging from topological insulator, Weyl semimetal to fractional Chern insulator. The unique, high-quality two-dimensional metallization process is based on our recent findings of the long-distance, non-Fickian in-plane mass transport and chemistry in 2D that occur at relatively low temperatures and in devices fully encapsulated with inert insulating layers. Highly compatible with existing nanofabrication techniques for van der Waals stacks, our results offer a route to designing and engineering superconductivity and topological phases in a class of correlated 2D materials. Published by the American Physical Society2024 

Functional thin films and interphases are omnipresent in modern technology and often determine the performance and life-time of devices. However, existing coating strategies are incompatible with emerging mesoscaled 3D architected and porous materials, and fail to uniformly apply functional thin films on their large and complex interior 3D surface. In this report, we introduce an approach for obtaining conformal polymeric thin films using custom-designed dual-functional monomers possessing both self-limiting electrodeposition capability and the functionality of interest in separate molecular motifs. We exemplify this approach with the monomer triethylene glycol-diphenol and demonstrate the full coating of a 3D mesoscaled battery electrode with an ultrathin lithium-ion permeable film. Our comprehensive study of the processing–structure–property relationships enables the tailorable control over the conformal thickness (7–80 nm), molecular permeability, and electronic properties. The modularity and tunability of this approach make it a promising candidate for functional polymer film deposition on arbitrary 3D structures. 

Abstract Liquid metals, such as Gallium‐based alloys, have unique mechanical and electrical properties because they behave like liquid at room temperature. These properties make liquid metals favorable for soft electronics and stretchable conductors. In addition, these metals spontaneously form a thin oxide layer on their surface. Applications made possible by this delicate oxide skin include shape reconfigurable electronics, 3D‐printed structures, and unconventional actuators. This paper introduces a new approach where liquid metal oxide serves as an electrochemical energy source. By mechanically rupturing their surface oxide, liquid metals form a galvanic cell and convert their chemical energy to electrical energy. When dispersing liquid metals into an ionically‐conductive liquid to form emulsions, this composite material can provide ∼500 mV of open‐circuit voltage and up to ∼4 μWof power. Protected by the naturally occurring oxide skin, the passivating oxide layer of the liquid metal shields it from self‐discharge over time. The device is also stable in harsh environments, such as high temperature or aquatic conditions. Future applications of this device are demonstrated by designing a strain‐activated stretchable battery and a pressure‐sensitive self‐powered keypad. These findings may unlock new pathways to design stretchable batteries and harness their inherent energy for self‐powered robust devices.