@misc{JahnBlaudeckBaumannetal., author = {Jahn, Stephan F. and Blaudeck, Thomas and Baumann, Reinhard R. and Jakob, Alexander and Ecorchard, Petra and R{\"u}ffer, Tobias and Lang, Heinrich and Schmidt, Peer}, title = {Inkjet Printing of Conductive Silver Patterns by Using the First Aqueous Particle-Free MOD Ink without Additional Stabilizing Ligands}, series = {Chemistry of Materials}, volume = {22}, journal = {Chemistry of Materials}, number = {10}, issn = {1520-5002}, doi = {10.1021/cm9036428}, pages = {3067 -- 3071}, abstract = {The chemical and physical properties of [AgO2C(CH2OCH2)3H] (3) and its use as an aqueous, ligand-free MOD ink (MOD = metal-organic decomposition) for piezo inkjet printing is discussed. The printed, thermal, or photochemical sintered silver features are electrically conductive on glass (2.7 × 107 S m-1) and PET (PET = polyethylene terephthalate) substrates (1.1 × 107 S m-1) corresponding to 43\% and 18\% of the bulk silver conductivity. Conducted tape tests show the suitability of the ink for particularly polymer substrates. TG-MS studies demonstrate a two-step decomposition for the conversion of 3 to elemental silver. The structure of 3 in the solid state was determined by single X-ray structure determination.}, language = {en} } @misc{JahnJakobBlaudecketal., author = {Jahn, Stephan F. and Jakob, Alexander and Blaudeck, Thomas and Schmidt, Peer and Lang, Heinrich and Baumann, Reinhard R.}, title = {Inkjet printing of conductive patterns with an aqueous solution of [AgO2C(CH2OCH2)3H] without any additional stabilizing ligands}, series = {Thin Solid Films}, volume = {518}, journal = {Thin Solid Films}, number = {12}, issn = {0040-6090}, doi = {10.1016/j.tsf.2010.01.030}, pages = {3218 -- 3222}, abstract = {The use of silver(I)-2-[2-(2-methoxyethoxy)ethoxy]acetate, [AgO2C(CH2OCH2)3H], and its application as an aqueous metal-organic decomposition (MOD) inkjet ink is reported. The chemical and physical properties of the silver carboxylate and the ink formulated thereof are discussed. The ink meets all requirements of piezo driven inkjet printing. The printed features were converted into electrically conducting silver patterns by thermal or photo-thermal treatment. The conversion of [AgO2C(CH2OCH2)3H] to elemental silver follows a two-step decomposition as demonstrated by thermogravimetry-mass spectrometry (TG-MS) measurements. The measured conductivities of the printed features on glass and polyethylene-terephthalate (PET) are 2.7 × 107 S m-1 and 1.1 × 107 S m-1, respectively, which correspond to 43\% (glass) and 18\% (PET) of the bulk silver conductivity.}, language = {en} } @misc{BischoffLeisePerezBoschQuesadaetal., author = {Bischoff, Carl and Leise, Jakob and Perez-Bosch Quesada, Emilio and P{\´e}rez, Eduardo and Wenger, Christian and Kloes, Alexander}, title = {Implementation of device-to-device and cycle-to-cycle variability of memristive devices in circuit simulations}, series = {Solid-State Electronics}, volume = {194}, journal = {Solid-State Electronics}, issn = {0038-1101}, doi = {10.1016/j.sse.2022.108321}, pages = {4}, abstract = {We present a statistical procedure for the extraction of parameters of a compact model for memristive devices. Thereby, in a circuit simulation the typical fluctuations of the current-voltage (I-V) characteristics from device-to-device (D2D) and from cycle-to-cycle (C2C) can be emulated. The approach is based on the Stanford model whose parameters play a key role to integrating D2D and C2C dispersion. The influence of such variabilities over the model's parameters is investigated by using a fitting algorithm fed with experimental data. After this, the statistical distributions of the parameters are used in a Monte Carlo simulation to reproduce the I-V D2D and C2C dispersions which show a good agreement to the measured curves. The results allow the simulation of the on/off current variation for the design of RRAM cells or memristor-based artificial neural networks.}, language = {en} } @misc{HessvonWerderHarrisonetal., author = {Hess, Alexander J. and von Werder, Dina and Harrison, Olivia K. and Heinzle, Jakob and Stephan, Klaas Enno}, title = {Refining the allostatic self-efficacy theory of fatigue and depression using causal inference}, series = {Entropy}, volume = {26 (2024)}, journal = {Entropy}, number = {12}, publisher = {MDPI AG}, issn = {1099-4300}, doi = {10.3390/e26121127}, pages = {1 -- 18}, abstract = {Allostatic self-efficacy (ASE) represents a computational theory of fatigue and depression. In brief, it postulates that (i) fatigue is a feeling state triggered by a metacognitive diagnosis of loss of control over bodily states (persistently elevated interoceptive surprise); and that (ii) generalization of low self-efficacy beliefs beyond bodily control induces depression. Here, we converted ASE theory into a structural causal model (SCM). This allowed identification of empirically testable hypotheses regarding causal relationships between the variables of interest. Applying conditional independence tests to questionnaire data from healthy volunteers, we sought to identify contradictions to the proposed SCM. Moreover, we estimated two causal effects proposed by ASE theory using three different methods. Our analyses identified specific aspects of the proposed SCM that were inconsistent with the available data. This enabled formulation of an updated SCM that can be tested against future data. Second, we confirmed the predicted negative average causal effect from metacognition of allostatic control to fatigue across all three different methods of estimation. Our study represents an initial attempt to refine and formalize ASE theory using methods from causal inference. Our results confirm key predictions from ASE theory but also suggest revisions which require empirical verification in future studies.}, language = {en} } @misc{KloesBischoffLeiseetal., author = {Kloes, Alexander and Bischoff, Carl and Leise, Jakob and Perez-Bosch Quesada, Emilio and Wenger, Christian and P{\´e}rez, Eduardo}, title = {Stochastic switching of memristors and consideration in circuit simulation}, series = {Solid State Electronics}, volume = {201}, journal = {Solid State Electronics}, issn = {0038-1101}, doi = {10.1016/j.sse.2023.108606}, abstract = {We explore the stochastic switching of oxide-based memristive devices by using the Stanford model for circuit simulation. From measurements, the device-to-device (D2D) and cycle-to-cycle (C2C) statistical variation is extracted. In the low-resistive state (LRS) dispersion by D2D variability is dominant. In the high-resistive state (HRS) C2C dispersion becomes the main source of fluctuation. A statistical procedure for the extraction of parameters of the compact model is presented. Thereby, in a circuit simulation the typical D2D and C2C fluctuations of the current-voltage (I-V) characteristics can be emulated by extracting statistical parameters of key model parameters. The statistical distributions of the parameters are used in a Monte Carlo simulation to reproduce the I-V D2D and C2C dispersions which show a good agreement to the measured curves. The results allow the simulation of the on/off current variation for the design of memory cells or can be used to emulate the synaptic behavior of these devices in artificial neural networks realized by a crossbar array of memristors.}, language = {en} }