The use of paper as a material for various device applications (such as microfluidics and energy storage) is very attractive given its flexibility, versatility, and low cost. Here we demonstrate that electrowetting (EW) devices can be readily fabricated on paper substrates. Several categories of paper have been investigated for this purpose, with the surface coating, roughness, thickness, and water uptake, among the most important properties. The critical parameter for EW devices is the water contact angle (CA) change with applied voltage. EW devices on paper exhibit characteristics very close to those of conventional EW devices on glass substrates. This includes a large CA change in oil ambient (90-95°), negligible hysteresis (∼2°), and fast switching times of ∼20 ms. These results indicate the promise of low-cost paper-based EW devices for video rate flexible e-paper on paper.
The appearance of spin-density-wave (SDW) magnetic order in the low-temperature and high-field corner of the superconducting phase diagram of CeCoIn 5 is unique among unconventional superconductors. The nature of this magnetic Q phase is a matter of current debate. Here, we present the thermal conductivity of CeCoIn 5 in a rotating magnetic field, which reveals the presence of an additional order inside the Q phase that is intimately intertwined with the superconducting d-wave and SDW orders. A discontinuous change of the thermal conductivity within the Q phase, when the magnetic field is rotated about antinodes of the superconducting d-wave order parameter, demands that the additional order must change abruptly, together with the recently observed switching of the SDW. A combination of interactions, where spin-orbit coupling orients the SDW, which then selects the secondary p-wave pair-density-wave component (with an average amplitude of 20% of the primary d-wave order parameter), accounts for the observed behavior.
A nano‐sized two‐terminal memristor exhibiting volatile threshold switching (TS) is a promising candidate for the emulation of biological synaptic functions to realize efficient neuromorphic computing systems. The Ca2+ dynamics play a vital role in generating a temporal response for neural functions by changing the synaptic weight of biological synapses. Herein, a thinnest synaptic device is fabricated demonstrating drift dynamics of Ag+ migration through the exfoliated h‐BN sheets, which emulates neuromorphic computing operations. The TS characteristics with a large ION/OFF up to ≈105 lead to bio‐synaptic applications, including short‐term and long‐term memory. The experimental realization of the synaptic behavior is demonstrated with paired‐pulse facilitation (PPF), spike‐rate‐dependent plasticity (SRDP), and transition from short‐term plasticity (STP) to long‐term plasticity (LTP). The transition from STP to LTP in this synaptic device verifies the Atkinson and Shiffrin psychological model of human brain learning experimentally. The input pulses with different spike‐times are used to replicate the synaptic functionalities. The two‐terminal diffusive memristors constructed with thin sheets of 2D‐flexible h‐BN resistive materials may lead to flexible neuromorphic devices for biological applications.
There is great interest in µfluidic devices due to important applications ranging from biotechnology [1] to flat panel displays [2]. An important enabling technology in µfluidics is based on the electrowetting (EW) effect [3], which controls the contact angle of a liquid on a hydrophobic surface through the application of an electric field. Many operations can be performed through external control [4] (such as droplet dispensing, transport, splitting, and mixing), leading to increasingly sophisticated applications for lab-on-chip [5] devices. One of the limitations of µfluidic devices is that the information contained in the fluid has to be converted in an electronic form in order to interact with our pervasive digital world. This conversion typically is performed through either direct optical sensing or combined with optical excitation of fluorescent dyes, which is cumbersome, limited in information processing, and expensive. We have invented [6] an EW-based liquid state field effect transistor (LiquiFET), which is very similar in concept to conventional semiconductor FETs but operates in the liquid state and thus can directly convert charge-related information from the liquid state into conventional electronic signals. Fig. 1 illustrates the LiquiFET structure and current control achieved by EW between competitive conducting/insulating fluids. Fig. 1 Schematics of LiquiFET structure: (a) cross section in off state, (b) cross section in on state, (c) top view in off state, and (d) top view in on state.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.