Dual-function Device Research Articles

Dual-function tuneable asymmetric transmission and polarization converter in terahertz region

We theoretically demonstrated a switchable, as well as tuneable, asymmetric transmission and reflective polarization conversion device in terahertz region. The proposed dual-function device composed of vanadium dioxide (VO2) and Dirac semimetal (DSM) metamaterials (MMs). Switching is achieved by exploiting the dielectric-to-metal phase transition of VO2 board. On the one hand, the hybrid MMs structure behave as a transmission device when VO2 board in its insulating phase and VO2 grating in its metallic phase. In this case, broadband asymmetric transmission of linear polarization has been realised in the range of 2.023–5.971 THz. On the other hand, this hybrid metamaterial acts as a reflective device when VO2 board in its metallic phase and VO2 grating in its insulating phase. In this situation, linear-to-circular polarization conversion has been achieved in the ranges 2.058–3.423 and 4.753–5.6 THz, and at 6.496 THz. In each of the above working modes, tuneable spectral response has been achieved by modifying the Fermi energy of DSM materials. The device also exhibits a robust polarization conversion performance with the incident angle less than 40°. Dual-function metamaterial like the one presented here may find applications in active polarization controller, asymmetric transmission device, broadband and multiband filters, and other tuneable modulators.

High-performance and robust dual-function electrochromic device for dynamic thermal regulation and electromagnetic interference shielding

• A dual-function EC device with dynamic thermal regulation and EMI shielding simultaneously is first constructed. • The doping mechanism and EC mechanism of PANI are discussed in detail. • This flexible device exhibits excellent EMI shielding, thermal regulation and the high stability under mechanical stimulus. High-performance devices with the electromagnetic interference (EMI) shielding and dynamic thermal regulation performances are highly desirable for modern integrated electronic and telecommunication systems in areas such as aerospace, communication equipment, and smart electronics. Herein, the dual-function electrochromic (EC) device is fabricated using the polyaniline (PANI) film as the infrared (IR) EC layer, the polymethyl methacrylate (PMMA) gel polymer as the electrolyte and the MXene/PANI/poly vinylidene fluoride (PVDF)/Au (MPPA) film as the EMI shielding layer. The device exhibits a superior EMI shielding effectiveness (SE) of 36.5 dB at 11.6 GHz, benefiting from the highly efficient conductive porous structure, as well as excellent dynamic thermal regulation performances by manipulating emittance (emittance modulation of 0.39 at 8–14 μm), which could also achieve the dynamic heating or cooling of the practical object. Moreover, the performances of the device show no obvious degradation even under 650 cycles bending and 500 cycles twisting, indicating the high robustness. These results indicate that the dual-function device has promising potential for high-performance EMI shielding and thermal management applications.

Colloidal quantum dot lasers

Semiconductor nanocrystals represent a promising class of solution-processable optical-gain media that can be manipulated via inexpensive, easily scalable colloidal techniques. Due to their extremely small sizes (typically <10 nm), their properties can be directly controlled via effects of quantum confinement; therefore, they are often termed colloidal quantum dots (CQDs). In addition to size-tunable emission wavelengths, CQDs offer other benefits for lasing applications, including low optical-gain thresholds and high temperature stability of lasing characteristics. Recent progress in understanding and practical control of processes impeding light amplification in CQDs has resulted in several breakthroughs, including the demonstration of optically pumped continuous-wave lasing, the realization of optical gain with direct current electrical injection and the development of dual-function electroluminescent devices that also operate as optically pumped lasers. The purpose of this Review is to assess the status of the field of CQD lasing and discuss the existing challenges and opportunities. A particular focus is on approaches for suppressing nonradiative Auger recombination, novel optical-gain concepts enabled by strong exciton–exciton interactions and controlled CQD charging, effects of nanocrystal form factors on light amplification and practical architectures for realizing electrically pumped CQD lasers. This overview suggests that the accumulated knowledge, along with the approaches developed for manipulating the optical-gain properties of colloidal nanostructures, perfectly position the CQD field for successfully addressing a long-standing challenge: the realization of CQD-based laser diodes.

Reconfigurable Perovskite LEC: Effects of Ionic Additives and Dual Function Devices (Advanced Optical Materials 3/2021)

Reconfigurable Perovskite LEC: Effects of Ionic Additives and Dual Function Devices (Advanced Optical Materials 3/2021)

Gaussian-preserved, non-volatile shape morphing in three-dimensional microstructures for dual-functional electronic devices

Motile plant structures such as Mimosa pudica leaves, Impatiens glandulifera seedpods, and Dionaea muscipula leaves exhibit fast nastic movements in a few seconds or less. This motion is stimuli-independent mechanical movement following theorema egregium rules. Artificial analogs of tropistic motion in plants are exemplified by shape-morphing systems, which are characterized by high functional robustness and resilience for creating 3D structures. However, all shape-morphing systems developed so far rely exclusively on continuous external stimuli and result in slow response. Here, we report a Gaussian-preserved shape-morphing system to realize ultrafast shape morphing and non-volatile reconfiguration. Relying on the Gaussian-preserved rules, the transformation can be triggered by mechanical or thermal stimuli within a microsecond. Moreover, as localized energy minima are encountered during shape morphing, non-volatile configuration is preserved by geometrically enhanced rigidity. Using this system, we demonstrate a suite of electronic devices that are reconfigurable, and therefore, expand functional diversification.

Spectroscopic Techniques versus Pitot Tube for the Measurement of Flow Velocity in Narrow Ducts.

In order to assess the limits and applicability of Pitot tubes for the measurement of flow velocity in narrow ducts, e.g., biomass burning plants, an optical, dual function device was implemented. This sensor, based on spectroscopic techniques, targets a trace gas, injected inside the stack either in bursts, or continuously, so performing transit time or dilution measurements. A comparison of the two optical techniques with respect to Pitot readings was carried out in different flow conditions (speed, temperature, gas composition). The results of the two optical measurements are in agreement with each other and fit quite well the theoretical simulation of the flow field, while the results of the Pitot measurements show a remarkable dependence on position and inclination of the Pitot tube with respect to the duct axis. The implications for the metrology of small combustors’ emissions are outlined.

Reconfigurable Perovskite LEC: Effects of Ionic Additives and Dual Function Devices

AbstractHybrid organic–inorganic perovskite light‐emitting devices (LEDs) have recently shown the characteristic dynamical behavior of light‐emitting electrochemical cells (LECs), with intrinsic ionic migration creating an electric double layer and internal p‐i‐n structure and by accumulation of ions at interfaces. Therefore, the development of perovskite light‐emitting and photovoltaic devices based on the concepts of LEC operation attracts much attention and clarifies general physical processes in perovskites. Here, new directions that can further improve perovskite optoelectronic devices and extend their functionalities using additive mobile ions are overviewed: 1) enhancing single‐layer LECs with lithium additives for increased efficiency and longer lifetime; 2) facilitating ionic motion in three‐layer perovskite LECs to create dual‐functional devices, operating as both LEC and solar cells; and 3) creating truly ambipolar LEC devices with carbon nanotubes as stable electrodes that leverage ionic doping. Taken together, the use of these approaches provides a strategy to create efficient, stable, and bright LECs, which use advantages of both LED and LEC operation. It is discussed that how the LEC behavior in perovskite LEDs can be further improved to address the long‐term challenges in perovskite optoelectronics, such as stability, through approaches like ionically reconfigurable host/guest systems.

Development and processing of novel heparin binding functionalized modified spider silk coating for catheter providing dual antimicrobial and anticoagulant properties

Tailored surface coatings have been used for decades to improve material performance in blood. Among different approaches, heparin based biomedical coatings have found great success in the commercial catheter market. However, they have their own limitations. Coating of a vascular device with a heparin binding peptide (HBP), which can sequester the circulating heparin, presents numerous advantages over both systemic heparin therapy and direct heparin bound surfaces. Embedding HBP in a silk biopolymer provides the mechanical integrity necessary under dynamic flow conditions to both insert the catheter and maintain proper blood flow. Furthermore, due to the similarity in structure of HBP with antimicrobial peptides, it is predicted that the fusion protein will also show antimicrobial property, a critical and unique aspect to combat catheter related blood stream infections and extend the longevity of hemodialysis catheters. To assess this hypothesis, a recombinant fusion protein (S4H4) containing both silk amino acid motifs and HBP was assessed as a coating on a silicone surface. After validating that, the protein was deposited on the surface via XPS, Raman spectroscopy, ATR and SEM imaging, antimicrobial and anticoagulant activities were evaluated. The coating was able to prevent not only planktonic bacterial growth but also prevented the growth of a biofilm. Finally, the coating had both antibacterial and anticoagulant effect simultaneously. This study proves the successful production of a silk-based biopolymer that can be embedded with a heparin-binding functionality to create a dual functional device coating that can prevent infection and thrombosis together.

Evaluation of the safety and efficacy of suction-tip forceps, a new tool for laparoscopic surgery, for gastric cancer.

IntroductionLaparoscopic surgery is a minimally invasive surgery; however, obstacles to its functional optimization remain. Surgical ports can accommodate only one instrument at a time so complex exchange manipulations are necessary during surgery which increases operation times and patient risk. We developed a new laparoscopic instrument that functions as both forceps and a suction tube, which renders intraoperative tool exchange unnecessary. This pilot study was undertaken to evaluate the safety and efficacy of this novel dual‐function device in laparoscopic surgery for gastric cancer.MethodsThis single‐center pilot study assessed patient safety during and after laparoscopic distal gastrectomy for gastric cancer with the suction‐forceps using intraoperative video and clinical follow‐up, respectively. To evaluate instrument efficacy, we measured the time interval between the start of any bleeding and the start of aspiration (“suction access time”) and compared this time with that of a conventional surgical setup.ResultsIn total 15 patients participated, with all procedures being successful. No excess tissue damage occurred during surgery. Suction access time was significantly shorter in cases of bleeding when the suction‐tip forceps were used for aspiration (2.01 seconds) compared to an ordinary suction tube (12.5 seconds; P < .01).ConclusionThese findings suggest that our new suction‐tip forceps are a useful, safe, and efficacious operative tool. This surgical innovation may considerably simplify gastric laparoscopic surgery. This pilot study was registered with Japan Clinical Trial Registration on 22 June 2017 (registration number: UMIN000027879).

Tacsac: A Wearable Haptic Device with Capacitive Touch-Sensing Capability for Tactile Display

This paper presents a dual-function wearable device (Tacsac) with capacitive tactile sensing and integrated tactile feedback capability to enable communication among deafblind people. Tacsac has a skin contactor which enhances localized vibrotactile stimulation of the skin as a means of feedback to the user. It comprises two main modules—the touch-sensing module and the vibrotactile module; both stacked and integrated as a single device. The vibrotactile module is an electromagnetic actuator that employs a flexible coil and a permanent magnet assembled in soft poly (dimethylsiloxane) (PDMS), while the touch-sensing module is a planar capacitive metal-insulator-metal (MIM) structure. The flexible coil was fabricated on a 50 µm polyimide (PI) sheet using Lithographie Galvanoformung Abformung (LIGA) micromoulding technique. The Tacsac device has been tested for independent sensing and actuation as well as dual sensing-actuation mode. The measured vibration profiles of the actuator showed a synchronous response to external stimulus for a wide range of frequencies (10 Hz to 200 Hz) within the perceivable tactile frequency thresholds of the human hand. The resonance vibration frequency of the actuator is in the range of 60–70 Hz with an observed maximum off-plane displacement of 0.377 mm at coil current of 180 mA. The capacitive touch-sensitive layer was able to respond to touch with minimal noise both when actuator vibration is ON and OFF. A mobile application was also developed to demonstrate the application of Tacsac for communication between deafblind person wearing the device and a mobile phone user who is not deafblind. This advances existing tactile displays by providing efficient two-way communication through the use of a single device for both localized haptic feedback and touch-sensing.

A Six-Port Dual-Function RF Device With Four-Element MIMO Antenna Array and Bandpass Filter Operations

This article presents a dual-function RF device, with four antenna ports and two filter ports, which behaves either as a multiple-input multiple-output (MIMO) antenna array or a bandpass filter. It consists of four parallel-coupled microstrip lines as the dual-function part and two feed parts for the two channels. The former part simultaneously performs wideband array radiator and fourth-order filter resonator characteristics. For MIMO antenna array operation, the parallel-coupled microstrip line structure is equivalent to a traditional patch, which is divided into four strips with three slots. Based on such a configuration, wide antenna impedance bandwidth is achieved. With regard to the filter operation, it features a conventional fourth-order microstrip parallel-coupled filter typology. As a result, high circuit integration is achieved, and although the two channels share the common part, the bandwidth improvement for both the channels is realized. For demonstration, the proposed dual-function device is implemented and fabricated. As an MIMO antenna array, the center frequency and the measured impedance bandwidth is 4.5 GHz and 27.3%, respectively. The isolation between the two channels in this band is more than 23.6 dB. In addition, it features ±45° continuous beam scanning capacity with less than 3 dB gain reduction. With respect to the bandpass filter operation, the center frequency and measured impedance bandwidth is 0.55 GHz and 15.6%, respectively. The measured in-band insertion loss is 2.12 dB and channel isolation is more than 58 dB.

Polymer-Based Functional Cantilevers Integrated with Interdigitated Electrode Arrays-A Novel Platform for Cardiac Sensing.

Heart related ailments are some of the most common causes for death in the world, and some of the causes are cardiac toxicity due to drugs. Several platforms have been developed in this regard over the years that can measure electrical or mechanical behavior of cardiomyocytes. In this study, we have demonstrated a biomedical device that can simultaneously measure electrophysiology and contraction force of cardiomyocytes. This dual-function device is composed of a photosensitive polymer-based cantilever, with a pair of metal-based interdigitated electrodes on its surface, such that the cantilever can measure the contraction force of cardiomyocytes and the electrodes can measure the impedance between cells and substrate. The cantilever is patterned with microgrooves so that the cardiomyocytes can align to the cantilever in order to make a higher cantilever deflection in response to contraction force. Preliminary experimental results have identified the potential for use in the drug-induced cardiac toxicity tests, and further optimization is desirable to extend the technique to various bio-sensor areas.

Magnesium-Based Metasurfaces for Dual-Function Switching between Dynamic Holography and Dynamic Color Display.

Metasurface-based color display and holography have greatly advanced the state of the art display technologies. To further enrich the metasurface functionalities, recently a lot of research endeavors have been made to combine these two display functions within a single device. However, so far such metasurfaces have remained static and lack tunability once the devices are fabricated. In this work, we demonstrate a dynamic dual-function metasurface device at visible frequencies. It allows for switching between dynamic holography and dynamic color display, taking advantage of the reversible phase transition of magnesium through hydrogenation and dehydrogenation. Spatially arranged stepwise nanocavity pixels are employed to accurately control the amplitude and phase of light, enabling the generation of high-quality color prints and holograms. Our work represents a paradigm toward compact and multifunctional optical elements for future display technologies.

Light-sensitive charge storage medium with spironaphthooxazine molecule-polymer blends for dual-functional organic phototransistor memory

Abstract Organic phototransistor memory is considered as a promising optoelectronic device owing to its multifunctionality. However, due to the poor reliability of each function and the complexity of the device structure, it is necessary to optimize the thin-film process of functional materials when constructing multiple functions into a single device. Here, we demonstrate a dual-functional device that is both a working memory transistor and a phototransistor by incorporating photochromic spironaphthooxazine molecules into an organic insulating layer. The photochromic molecules in the polymer matrix not only exhibit nonvolatile charge storage properties similar to nano-floating gates but also feature a reversible electronic band structure upon alternating irradiation with ultraviolet and visible light, which makes the device function as both an electrical memory transistor and a phototransistor. Furthermore, the photoresponsive charge trap layer in the demonstrated device leads to excellent memory performance under both dark and light conditions, which includes a large memory window (~56 V), stable endurance cycles (>102), and good retention characteristics (>104 s). Our findings suggest an alternative strategy to realize organic multifunctional nonvolatile memories.

Graphene Sandwich Stable Perovskite Quantum-Dot Light-Emissive Ultrasensitive and Ultrafast Broadband Vertical Phototransistors.

Dual-functional devices that can simultaneously detect light and emit light have a tremendous appeal for multiple applications, including displays, sensors, defense, and high-speed optical communication. Despite the tremendous efforts of scientists, the progress of integration of a phototransistor, where the built-in electric field separates the photogenerated excitons, and a light-emitting diode, where the radiative recombination can be enhanced by band offset, into a single device remains a challenge. Combining the superior properties of perovskite quantum dots (PQDs) and graphene, here we report a light-emissive, ultrasensitive, ultrafast, and broadband vertical phototransistor that can simultaneously act as an efficient photodetector and light emitter within a single device. The estimated value of the external quantum efficiency of the vertical phototransistor is ∼1.2 × 1010% with a photoresponsivity of >109 A W-1 and a response time of <50 μs, which exceed all the presently reported vertical phototransistor devices. We also demonstrate that the modulation of the Dirac point of graphene efficiently tunes both amplitude and polarity of the photocurrent. The device exhibits a green emission having a quantum efficiency of 5.6%. The moisture-insensitive and environmentally stable, light-emissive, ultrafast, and ultrasensitive broadband phototransistor creates a useful route for dual-functional optoelectronic devices.

Dual-functional melatonin releasing device loaded with PLGA microparticles and cyclodextrin inclusion complex for osteosarcoma therapy

The aim of this study is to develop a scaffold-based device in which both osteoinductive and anticarcinogenic properties of melatonin can be combined for osteosarcoma therapy. While a high melatonin concentration and fast release are needed to achieve an anticancer effect, a low melatonin concentration and long-term release are necessary for bone regeneration. Long-term controlled release of melatonin was provided by the incorporation of melatonin-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles into the chitosan/hydroxyapatite (chitosan/HAp) scaffolds. This system showed a biphasic melatonin release-pattern with a burst release within 24 h, and then, a sustained release for 40 days that resulted into ∼40–70 μM concentration. Preosteoblastic MC3T3-E1 cells were cultured on this 3D device, and released melatonin caused increase in the expressions of osteogenic differentiation markers. For the inhibition of MG-63 human osteosarcoma cells, a melatonin/2-hydroxypropyl-β-cyclodextrin (HPβCD) inclusion complex was prepared by microwave technology to load a high amount of melatonin and provide fast release. Melatonin/HPβCD inclusion complex was incorporated into the chitosan/HAp scaffolds and loaded melatonin was rapidly released within 5 h and inhibited the proliferation of MG-63 cells in the G0/G1 phase. In conclusion, this melatonin-releasing scaffold-based device including melatonin-loaded PLGA microparticles and melatonin/HPβCD inclusion complex can be considered as a promising system for osteosarcoma therapy.

Dual-functional light-emitting perovskite solar cells enabled by soft-covered annealing process

Solution-processable perovskite semiconductors have demonstrated excellent performance in both perovskite solar cells (PeSCs) and perovskite light emitting diodes (PeLEDs). Their low exciton binding energy and excellent charge transport properties allow the conversion of photons into free electrons and holes and vice versa with minimal energy loss. In addition, planar PeSCs and PeLEDs have similar device architecture. These aspects inspired us to fabricate a dual-functional device with both SC and LED functions, here termed a light-emitting perovskite solar cells (LEPeSCs). However, the absence of an effective fabrication method to control grain size, uniformity, grain boundaries, and coverage of perovskite film inevitably limits device performance of dual-functional LEPeSCs. Here, we have demonstrated an efficient dual-functional LEPeSCs with planar device configuration of ITO/PEDOT:PSS/CH3NH3PbBrI2/PC61BM/Ca/Al, which is able to reversibly convert luminous energy to electric energy or electric energy to luminous energy in a single device. By developing a new soft-covered annealing method, we obtained optimized grain morphology with large grain size, high uniformity, and decreased grain boundaries, which is difficult to achieve with conventional fabrication methods. The LEPeSCs exhibits high performance in both PeSCs and PeLEDs modes, with power conversion efficiency of 14.02% in SC mode and bright red-light emission of 1710 cd/cm2 at 4 V in LED mode.

Light-emitting perovskite solar cell with segregation enhanced self doping

Organic-inorganic halide perovskites recently have emerged as a promising material for highly effective light-emitting diodes (LEDs) and solar cells (SCs). Despite efficiencies of both perovskite SCs and LEDs are already among the best, the development of a perovskite dual functional device that is capable of working in these two regimes with high efficiencies is still challenging. Here we demonstrate that the dual functional device based on mixed halide perovskite CH3NH3PbBr2I can be switched from SC to LED with low threshold voltage Vth < 2 V by exposing to Sun at open circuit Voc or at small bias voltage of Vpol ∼ 1–2 V. Such photo-poling creates in-situ p-i-n junction via methylammonium (CH3NH3+, MA+) and I−/Br− ions migration to interfaces, lowering charge injection barriers, and self-balancing injection currents in perovskite LED. We show that before the photo-poling, the electroluminescence (EL) is highly unstable in LED regime, whereas after the photo-poling, stabilized EL exhibits unusual dynamics, increasing with time and poling cycle number, while Vth and injection current decrease with cycling runs. Additionally, photo-induced and current-induced halide segregation accumulates with cycling, that is found beneficial for LED, increasing its efficiency and brightness, but reversibly degrading photovoltaic performance, which can be easily recovered.

Unify Energy Harvesting and Vibration Control Functions in Randomly Excited Structures with Electromagnetic Devices

AbstractWith the extensive studies on energy harvesting via electromagnetic devices in civil or mechanical structures, a novel dual-function device, termed electromagnetic damping and energy harves...

Novel electrochromic-fluorescent bi-functional devices based on aromatic viologen derivates

Novel electrochromic-fluorescent dual functional devices based on aryl substituted viologen derivates were fabricated and characterized. The devices containing four viologen derivates, had both electrochromic and fluorescent switching properties. They were designed and functionally synthesized by introducing benzene, naphthalene, anthracene and benzothiadiazole rings between two pyridine rings, which endowed these viologen derivates with unique photoelectric properties. Devices consisted of benzene viologen, naphthalene viologen and benzothiadiazole viologen revealed exceptional electrochromic properties, of vivid color changes, high optical contrast and fast response time under applied bias. In addition, owing to the increased conjugated π-framework degree of our designed compounds, compared to conventional viologens, the fabricated devices could all achieve intense fluorescence emission. Notably, outstanding cyclic stability of electrochromic devices over thousands cycles made these aromatic viologen derivates promising candidates for new generation electrochromic-fluorescent applications.