It has recently been suggested that movement variability directly increases the speed of motor learning. Here we use computational modeling of motor adaptation to show that variability can have a broad range of effects on learning, both negative and positive. Experimentally, we also find contributing and decelerating effects. Lastly, through a meta-analysis of published papers, we verify that across a wide range of experiments, movement variability has no statistical relation with learning rate. While motor learning is a complex process that can be modeled, further research is needed to understand the relative importance of the involved factors.

Today’s electronic devices are fabricated using highly toxic materials and processes which limits their applications in environmental sensing applications and mandates complex encapsulation methods in biological and medical applications. This paper proposes a fully resorbable high density bio-compatible and environmentally friendly solution processable memristive crossbar arrays using silk fibroin protein which demonstrated bipolar resistive switching ratio of 104 and possesses programmable device lifetime characteristics before the device gracefully bio-degrades, minimizing impact to environment or to the implanted host. Lactate dehydrogenase assays revealed no cytotoxicity on direct exposure to the fabricated device and support their environmentally friendly and biocompatible claims. Moreover, the correlation between the oxidation state of the cations and their tendency in forming conductive filaments with respect to different active electrode materials has been investigated. The experimental results and the numerical model based on electro-thermal effect shows a tight correspondence in predicting the memristive switching process with various combinations of electrodes which provides insight into the morphological changes of conductive filaments in the silk fibroin films.

The molecular packing motifs within crystalline domains should be a key determinant of charge transport in thin-fi lm transistors (TFTs) based on small organic molecules. Despite this implied importance, detailed information about molecular organization in polycrystalline thin fi lms is not available for the vast majority of molecular organic semiconductors. Considering the potential of fused thiophenes as environmentally stable, highperformance semiconductors, it is therefore of interest to investigate their thin fi lm microstructures in relation to the single crystal molecular packing and OTFT performance. have been scrutinized, such assumptions have been proven to sometimes be inaccurate, and it is now known that molecular packing in thin fi lms may differ signifi cantly from that in the bulk crystal structures, especially near the dielectric interface. For example, in thin fi lm form, both tetraceno[2,3-b]thiophene [ 17 ] and pentacene [ 16 ] exhibit a local molecular packing distinctly different from that in the bulk crystal. These observations highlight the necessity of obtaining microstructural details for thin organic fi lms.In this contribution, the molecular packing motifs of fi ve newly synthesized BTDT [ 9 ] derivatives ( Scheme 2 ), are studied both in bulk single crystals and in thin fi lms by single crystal diffraction and grazing incidence wide angle X-ray scattering (GIWAXS). We fi rst introduce the new BTDT molecules and describe their thermal, optical, and electrochemical properties. We then compare the bulk and thin fi lm structures by analyzing single-crystal X-ray diffraction and GIWAXS data. Lastly, the effect of thin fi lm microstructure on TFT performance is discussed. The results indicate that these BTDT derivatives have different molecular packing in thin fi lms versus the bulk crystals. In the case of P-BTDT , Bp-BTDT , Np-BTDT , and BBTDT , it will be seen that two types of lattices coexist, and that these are slightly strained compared to their bulk crystal forms. In contrast, for PF-BTDT fi lms, a single lattice is observed, however, this lattice has no apparent correspondence to the bulk crystal form. For P-BTDT , which yields the best performing TFTs of the series, the dominance of the more strained lattice relative to the bulk-like lattice may explain the excellent charge transport properties. On the other hand, poor crystallinity and poor surface coverage at the substrate interface explains the poor device performance of PF-BTDT fi lms. Results SynthesisDetails of the various BTDT syntheses can be found in the Supporting Information or previous literature. [ 9 ] Briefl y, the derivatives [ 2 , 9-14 ] offer a potential solution to this challenge, owing to their combination of suffi ciently high-lying excited states and high ionization potentials to suppress photo-oxidation, [ 11 ] and bulk single crystal packing motifs which are very similar to that of pentacene. Among organic semiconductor materials for p-channel devices, several fused thiophene derivatives with increased numb...

In this paper, we propose a scalable approach toward all-printed high-performance metal oxide thin-film transistors (TFTs), using a high-resolution electrohydrodynamic (EHD) printing process. Direct EHD micropatterning of metal oxide TFTs is based on diverse precursor solutions to form semiconducting materials (In2O3, In-Ga-ZnO (IGZO)), conductive metal oxide (Sn-doped In2O3 (ITO)), as well as aluminum oxide (Al2O3) gate dielectric at low temperatures. The fully printed TFT devices exhibit excellent electron transport characteristics (average electron mobilities of up to 117 cm2 V–1 s–1), negligible hysteresis, excellent uniformity, and stable operation at low-operating voltage. Furthermore, integrated logic gates such as NOT and NAND have been printed and demonstrated. All-printed logic with individual gating and symmetric input/output behavior, which is crucial for large-scale integration, is also demonstrated. The devices and fabrication process described in this paper enable high-performance and high-reliability transparent electronics.