Multicomponent Circuits Research Articles

Bistable organic electrochemical transistors: enthalpy vs. entropy

Organic electrochemical transistors (OECTs) underpin a range of emerging technologies, from bioelectronics to neuromorphic computing, owing to their unique coupling of electronic and ionic charge carriers. In this context, various OECT systems exhibit significant hysteresis in their transfer curve, which is frequently leveraged to achieve non-volatility. Meanwhile, a general understanding of its physical origin is missing. Here, we introduce a thermodynamic framework that readily explains the emergence of bistable OECT operation via the interplay of enthalpy and entropy. We validate this model through temperature-resolved characterizations, material manipulation, and thermal imaging. Further, we reveal deviations from Boltzmann statistics for the subthreshold swing and reinterpret existing literature. Capitalizing on these findings, we finally demonstrate a single-OECT Schmitt trigger, thus compacting a multi-component circuit into a single device. These insights provide a fundamental advance for OECT physics and its application in non-conventional computing, where symmetry-breaking phenomena are pivotal to unlock new paradigms of information processing.

Efficient Intracellular MicroRNA Imaging Based on the Localized and Self-Sustainable Catalytic DNA Assembly Circuit.

Building dynamic biological networks, especially DNA circuits, has provided a powerful prospect for exploring the intrinsic regulation processes of live cells. Nevertheless, for efficient intracellular microRNA analysis, the available multi-component circuits are constrained by their limited operating speed and efficiency due to the free diffusion of reactants. Herein, we developed an accelerated Y-shaped DNA catalytic (YDC) circuit for high-efficiency intracellular imaging of microRNA. By grafting the catalytic hairpin assembly (CHA) reactants into an integrated Y-shaped scaffold, the CHA probes were concentrated in a compact space, thus achieving high signal amplification. Profiting from the spatially confined reaction and the self-sustainably assembled DNA products, the YDC system facilitated reliable and in situ microRNA imaging in live cells. Compared with the homogeneously dispersed CHA reactants, the integrated YDC system could efficiently promote the reaction kinetics as well as the uniform delivery of CHA probes, thus providing a robust and reliable analytical tool for disease diagnosis and monitoring.

Calculation of DC Circuits Containing the Child-Langmuir Diodes

The DC circuits containing the Child-Langmuir (CL) diodes as their components are proposed for the first time for studying and calculation. The CL-diodes have a volt-ampere characteristic in the form of the power law with an exponent of 3/2. The devices that should be related to the category of CL-diodes include vacuum thermionic diodes with direct currents limited by the electron beam own space charge, solar cells, semiconductor light-emitting diodes, high-power diodes of direct-acting electron accelerators, etc. Circuits containing several CL-diodes have not been considered before anywhere. Formulas for general perveance with parallel- and series-connected CL-diodes having different perveances are given. Two calculation examples of the general perveance of the circuit containing three and four CL-diodes are presented. The methods and results of this study can be used for calculating the volt-ampere characteristics of, e.g., complex multicomponent circuits of solar cells or light emitting diodes.

Transcriptional readout of neuronal activity via an engineered Ca2+-activated protease

Molecular integrators, in contrast to real-time indicators, convert transient cellular events into stable signals that can be exploited for imaging, selection, molecular characterization, or cellular manipulation. Many integrators, however, are designed as complex multicomponent circuits that have limited robustness, especially at high, low, or nonstoichiometric protein expression levels. Here, we report a simplified design of the calcium and light dual integrator FLARE. Single-chain FLARE (scFLARE) is a single polypeptide chain that incorporates a transcription factor, a LOV domain-caged protease cleavage site, and a calcium-activated TEV protease that we designed through structure-guided mutagenesis and screening. We show that scFLARE has greater dynamic range and robustness than first-generation FLARE and can be used in culture as well as in vivo to record patterns of neuronal activation with 10-min temporal resolution.

Clinical Relevance of a Balance Training Program on Liver Transplant Patients. A Randomized Controlled Trial

Although some studies have reported significant improvements in physical function and strength after training programs on liver transplant (LT) recipients, there is a lack of knowledge on how it affects in static and dynamic balance, being an important part of these participants' tasks development. The aim of the study was to determine the effects of a 6-month multicomponent circuit training program on static and dynamic balance in LT participants. Fifty-four participants were randomized at 6 months after LT into 2 groups: exercise (EXER) group and control (CONTROL) group, with repeat testing at 6 (baseline) and 12 months after LT. The intervention consisted of a multicomponent training, including balance, strength, endurance, and flexibility training, with exercises arranged in a circuit setup and a moderate intensity with high perceived exertion. Training sessions were performed in the hospital facilities with qualified trainers. To determine differences over time between EXER and CONTROL, mixed-regression linear models with subject variable as random factor and variables of treatment duration, type, and interaction as predictors were used. The EXER group showed significant differences (P < 0.05) compared with CONTROL in all variables of static and dynamic balance, hip strength (49% versus 13%), agility (-16% versus -1%), and flexibility (78% versus -26%). Adherence to the intervention was 94%, and 80% of the participants continued voluntarily training after the 6 months. This study demonstrated that a multicomponent circuit training program at a moderate intensity with high perceived exertion could reduce the probability of injuries because it improves balance on LT recipients.

Inkjet Printed Circuits on Flexible and Rigid Substrates Based on Ambipolar Carbon Nanotubes with High Operational Stability.

Inkjet printed ambipolar transistors and circuits with high operational stability are demonstrated on flexible and rigid substrates employing semiconducting single-walled carbon nanotubes (SWCNTs). All patterns, which include electrodes, semiconductors, and vias, are realized by inkjet printing without the use of rigid physical masks and photolithography. An Al2O3 layer deposited on devices by atomic layer deposition (ALD) transforms p-type SWCNT thin-film transistors (TFTs) into ambipolar SWCNT TFTs and encapsulates them effectively. The ambipolar SWCNT TFTs have balanced electron and hole mobilities, which facilitates their use in multicomponent circuits. For example, a variety of logic gates and ring oscillators are demonstrated based on the ambipolar TFTs. The three-stage ring oscillator operates continuously for longer than 80 h under ambient conditions with only slight deviations in oscillation frequency. The successful demonstration of ambipolar devices by inkjet printing will enable a new class of circuits that utilize n-channel, p-channel, and ambipolar circuit components.

Solution Based Self‐Assembly of an Array of Polymeric Thin‐Film Transistors

Spontaneous self-organization of different materials from solution into an array of isolated and encapsulated thin-film-transistors (TFTs) is induced. We demonstrate the self-assembly of a 64 polymer TFT array with a yield higher than 95%. This work constitutes a first step towards self-assembly of multi-layer, multi-component circuits out of solution.