Decrease In Capacitance Research Articles

Influence of Oxygen Vacancies Introduced via Acceptor (Gadolinium) Doping to the Pseudocapacitive Properties of Nano-Sized Cerium Oxide.

The voluntary introduction of defects can be considered an effective strategy for enhancing the electrochemical properties of metal oxide electrodes. In this study, the enhanced pseudocapacitive properties of an acceptor (Gd) doped cerium oxide nanoparticle-a sustainable metal oxide with low environmental and human toxicity-are investigated in depth using ex situ X-ray photoemission spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Interestingly, with 15at% Gd doping (15GDC), the specific capacitance of the nanoparticles measured at 1Ag-1 enhanced to 547.8Fg-1, which is fivefold higher than undoped CeO2 (98.7Fg-1 at 1Ag-1). The rate-dependent capacitance is also improved for 15GDC, which showed a 31.0% decrease in the specific capacitance upon a tenfold increase in the current density, while CeO2 showed a 49.9% decrease. The enhanced electrochemical properties are studied in depth via ex situ XPS and EIS analysis, which revealed that the oxygen vacancies at the surface of the nanoparticles played important roles in enhancing both the specific capacitance and the high-rate performance of 15GDC by acting as the active site for pseudocapacitive redox reaction and allowing fast diffusion of oxygen ions at the surface of 15GDC nanoparticles.

Parylene Double-Layer Coated Screen-Printed Carbon Electrode for Label-Free and Reagentless Capacitive Aptasensing of Gliadin.

Celiac patients are required to strictly adhere to a gluten-free diet because even trace amounts of gluten can damage their small intestine and leading to serious complications. Despite increased awareness, gluten can still be present in products due to cross-contamination or hidden ingredients, making regular monitoring essential. With the goal of guaranteeing food safety for consuming labeled gluten-free products, a capacitive aptasensor was constructed to target gliadin, the main allergic gluten protein for celiac disease. The success of capacitive aptasensing was primarily realized by coating a Parylene double-layer (1000 nm Parylene C at the bottom with 400 nm Parylene AM on top) on the electrode surface to ensure both high insulation quality and abundant reactive amino functionalities. Under the optimal concentration of aptamer (5 μM) used for immobilization, a strong linear relationship exists between the amount of gliadin (0.01-1.0 mg/mL) and the corresponding ΔC response (total capacitance decrease during a 20 min monitoring period after sample introduction), with an R2 of 0.9843. The detection limit is 0.007 mg/mL (S/N > 5), equivalent to 0.014 mg/mL (14 ppm) of gluten content. Spike recovery tests identified this system is free from interferences in corn and cassava flour matrices. The analytical results of 24 commercial wheat flour samples correlated well with a gliadin ELISA assay (R2 = 0.9754). The proposed label-free and reagentless capacitive aptasensor offers advantages of simplicity, cost-effectiveness, ease of production, and speediness, making it a promising tool for verifying products labeled as gluten-free (gluten content <20 ppm).

Spatially resolved capacitance-based stress self-sensing in concrete

Spatially resolved capacitance-based stress self-sensing in unmodified concrete has been demonstrated. The spatial resolution is 45 mm in one dimension, which is in the direction of the capacitance measurement. Parallel coplanar component electrodes (aluminum, 5-mm wide), attached to the concrete using double-sided adhesive tape) separated by 45 mm are used to measure the in-plane capacitance in the direction perpendicular to the length of the electrodes. Combinations of component electrodes are electrically connected to form an electrode. The capacitance ranges from ∼200 pF to ∼750 pF. The greater is the number of component electrodes in an electrode, the higher is the capacitance. The compressive loading is applied at selected areas located between adjacent component electrodes. The stress (defined as load divided by the 300 ×300-mm2 concrete area) is up to 3000 Pa. The load decreases the capacitance monotonically and reversibly. The fractional decrease in capacitance ranges from ∼0.1 % to ∼0.5 %. More spatially concentrated loading, as for loading near the edges of the specimen, gives greater fractional decrease in capacitance. The capacitance decreases with increasing inter-electrode distance. Embedded steel rebars with a 20.0-mm concrete cover do not affect the capacitance or capacitance-based sensing.

The inhibitive action of lemon verbena plant extract as an economical and eco-friendly corrosion inhibitor for mild steel in acidic solutions

The inhibitive effect of lemon verbena (lemon v.) extract as a green corrosion inhibitor (CI) for mild steel (st37) in 0.5 M H2SO4 and 1 M HCl media at room temperature is investigated by employing electrochemical current noise (ECN), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and scanning electron microscopy (SEM). The achievements demonstrated that the inhibition efficiency increases with increasing the extract concentration up to 2000 ppm in 0.5 M H2SO4 and up to 2500 ppm in 1 M HCl solutions and decreases with an increase in temperature. The ECN results show when Lemon V. extract is included to both acidic media, the values of commotion charges (Q) diminished. The least value of the Q is 15 and 60 mCoul in H2SO4 and HCl media, respectively. The EIS measurements depicted that by addition of the inhibitors up to a certain concentration, the charge transfer resistance increases up to 186 Ω cm−2 in H2SO4 and 350 Ω cm−2 in HCl, besides the double layer capacitance (Cdl) decreases. Potentiodynamic polarization assessments indicated that Lemon V. acts as mixed type inhibitor. Certain thermodynamic parameters were determined based on the temperature impact on inhibition and corrosion processes. The extract adsorption on the surface of the alloy follow the Langmuir adsorption pattern. A mixed mode of adsorption was observed, wherein the extract in H2SO4 and HCl predominantly underwent chemisorption. Thermodynamic parameters indicated spontaneous adsorption and exothermic process with increasing entropy in H2SO4 and decreasing entropy in HCl. SEM investigation also validated the adsorption performance of the inhibitor.

Capacitance-based structural self-sensing of stress: effect of water/cement

The compressive stress self-sensing properties of mortars with different water-cement ratios are investigated without the need for any conductive additives. Mortar specimens are cyclically loaded and the corresponding capacitance and resistance are measured. The aluminum foil that is used as the electrode is wrapped around the prismatic sample. A coplanar configuration of electrodes is used. Capacitance and resistance increase with increasing water/cement (W/C) ratio. Stress causes decrease in capacitance and increase in resistance. The relationship between stress and fractional capacitance-resistance (except for the sample with 0.30 W C−1 ratio) change is reasonably consistent. The effectiveness of stress sensing (the fractional change in capacitance-resistance per unit of stress) decreases monotonically as the maximum stress increases, regardless of the W/C ratio. It is found that the dependence of the effectiveness of the stress sensing on the W/C ratio decreases with an increase in the maximum stress.

Quantum capacitance behavior of Ti2CO2/MoS2 heterostructures with 3d and 4d transition-metal doping

The storage capacity of capacity, quantum capacitance behavior, and atomic stability of O-defected, S-defected, 3d and 4d transition-metal (3d-TMs: Sc, Ti, V, Cr, Mn, Fe, Co, and Ni; 4d-TMs: Y, Zr, Nb, Mo, Ru, Rh, Pd, and Ag) doped Ti2CO2/MoS2 heterostructures were studied by density functional theory (DFT). Pristine Ti2CO2/MoS2 exhibited a high quantum capacitance of 1038.62 μF/cm2 at the positive potential. The appearance of O-vacancy in Ti2CO2-layer enhanced the capacitance of Ti2CO2/MoS2 at negative bias, and S-vacancy induced an obvious improvement of quantum capacitance at 0 V. After introducing various transition metals into modified Ti2CO2/MoS2 heterostructures, the doping in pristine structures increased the capacitance value to be 1182.71 μF/cm2 (Y-doping), while TM-doping in S-vacancy defected Ti2CO2/MoS2 systems induced a slight decrease of capacitance at positive potentials. For TM-doped O-defected Ti2CO2/MoS2, only Sc- and Y-doped systems exhibited higher quantum capacitance than the pristine Ti2CO2/MoS2, which were 1093.60 and 1096.26 μF/cm2. Due to the obvious advantage of capacitance of pristine Ti2CO2/MoS2 than Ti2CO2 or MoS2 single-layer at the positive bias, it can be used as effective anodes for high-capacitance supercapacitors, while 3d or 4d TM-doping had no significant enhancement in capacitance behaviors. The findings in this study were supposed to be theoretical data base to design high-performance supercapacitors.

Influence of Microwave and Magnetic Fields on the Electrophysical Parameters of a Tunnel Diode

In this paper, we studied the effect of an electromagnetic field of an ultrahigh frequency on the I–V characteristics of tunnel diodes. The influence of thermionic current on the change in the ratio of the values of tunnel currents at depth and the peak formed in the tunnel diode as a result of a strong electromagnetic field and on the change in the ratio of the values of tunnel currents at the highest and lowest points without exposure to a strong electromagnetic field. The I–V characteristics of a tunnel diode under the action of a microwave field is determined based on the theory of Knott and Demassa and the Tsu-Esaki model. The characteristics of the Tsu-Esaki and Karlovsky models used to determine the effect of the tunnel current in the extremely high frequency field (EHF) are shown. Chynoweth's model and Knott and Demassa's theory have shown that in germanium-based tunnel diodes, under an extremely high frequency (EHF) field, the amount of excess current generated in the tunnel diode increases. According to the Tsu-Esaki theory and Knott and Demassa theory is found to decrease the value of the differential resistance of a tunnel diode with a p-n junction under the action of a microwave field, regardless of the type of heterostructure or doping level. According to the Tsu-Esaki theory and Knott and Demassa found decrease in the diffusion capacitance of a tunnel diode with a p-n junction under the action of a microwave field, regardless of the type of heterostructure or doping level. A decrease in the transparency coefficient due to an increase in the internal field at the p-n junction boundary of a Ge-based tunnel diode under the action of a microwave field has been established. A formula is determined for determining the total current of a tunnel diode under the action of both microwave and magnetic fields, taking into account the transparency coefficient of the tunnel diode.

Long cycle life achieved in polyaniline/SP based self-healing supercapacitor

Polyaniline (PANI) has emerged as a promising electrode material for supercapacitors due to its low cost and high specific capacitance. However, during the charge and discharge process, PANI undergoes volume changes, leading to structural damage at the molecular level. This results in material pulverization, causing a loss of electronic contact with the electrode and, consequently, a decrease in capacitance. In this study, we employed ultrasonication-assisted growth of PANI on super-P (PANI/SP-US) to enhance the structural stability. At 1 A g−1, a high specific capacitance of 639 F g−1 was achieved. After 5000 charge-discharge cycles at 2 A g−1, the material retained 75.9% of its capacitance. More importantly, we further developed an effective strategy to incorporate a self-healing polymer (SHP) to fabricate a self-healing electrode. Due to the self-healing ability, the pulverized PANI/SP-US was able to be reconnected and restore electronic contact with the electrode substrate, thereby regaining specific capacitance and achieving excellent cycle life. The sphere-like shape of PANI/SP-US is also of benefit to the self-healing process. Symmetric and asymmetric self-healing devices based on PANI/SP-US and the self-healing polymer exhibited outstanding cyclic stability, retaining 107.9% and 108% of their capacitance, respectively, after 10,000 cycles at 2 A g−1. The self-healing device also exhibits good flexibility under bending, folding deformations. In addition, the device also shows good capacitance retention as the temperature shifted from 50°C to 0°C. This work underscores the significance of microstructure self-repair in enhancing cyclic stability and extends the application of self-healing devices to flexible and variable-temperature conditions.

Imaginary impedance due to hopping phenomena and evaluation of dopant ionization time in cryogenic metal-oxide-semiconductor devices on highly doped substrate

MOS capacitors fabricated on substrates with doping concentrations as high as 1018 cm−3 were characterized at 4.2 K. The highly doped substrate exhibited an intrinsic imaginary component of impedance at 4.2 K. The imaginary component is attributed to the time delay induced by hopping phenomena, leading to a decrease in the gate capacitance. Furthermore, we investigated the time constant associated with dopant ionization under depletion conditions and determined it to be 0.35 μs. An equivalent circuit model of the highly doped substrate at 4.2 K is also shown.

Tunable electrical and mechanical properties of anode foils for aluminum electrolytic capacitors prepared by additive manufacturing technology

An additive manufacturing technology was used to produce anode foils with different polystyrene microsphere (PSM). The effect of PSM addition in the range of 0–20 vol% on the specific capacitance and bending strength of the anode foils was investigated. Scanning electron microscopy analysis confirms the presence of pores in the anode foils, which is attributed to the addition of PSM. The porosity and pore diameter of the anode foils increase with increasing PSM content, resulting in an initial increase and then a decrease in specific capacitance, as well as a gradual increase in bending strength. At a PSM addition of 12.5 vol%, the anode foils exhibit a high specific capacitance of 0.927 μF/cm2 and a bending strength of over 120 times greater, meeting the specific capacitance and bending strength requirements for anode foils in aluminum electrolytic capacitors. These findings suggest that incorporating PSM into anode foils is an effective method for adjusting their specific capacitance and bending strength.

Flexible laser-induced graphene electrodes on polyimide film: Hybrid nanoflower-modified dielectric microjunctions for non-faradaic analysis

Laser-induced Graphene (LIG) electrodes on flexible substrates have attracted significant research interest, making them an excellent alternative to conventional fabrication of transducers on rigid planar substrates. In this study, four individual capacitor-like triangular LIG electrodes were fabricated on polyimide (PI) film with micron gap (MG) spacing of 30, 66, 125 and 180 µm, to study the relationship between gap spacing and capacitance. A novel N, N-carbonyldiimidazole-copper (CDI-Cu) hybrid nanoflower (NF) was synthesised via one-pot biomineralization and deposited at the triangular junction of acid-base treated LIG-MG for the immobilization of neutravidin. The gap spacing and structure of the LIG-MG were analysed using high-resolution microscopes, revealing a porous nanofiber-like graphene structure. X-ray Photoelectron Spectroscopy (XPS) of acid-base treated PI film proved carboxyl group formation. A decrease in capacitance was observed with an increasing gap spacing in a non-faradaic environment. The capacitance of CDI-Cu NF following neutravidin modification for 30, 66, 125 and 180 µm spacings were 1.77E-07, 1.36E-07, 4.73E-08, 4.84E-08 F, respectively, suggesting excellent biomolecular modification sensitivity of the LIG-MG with 30 µm spacing. A comparative analysis of dielectric performance for different gap-spaced devices revealed that a 30 µm spacing would be optimal for bio-capturing because of the close confinement of biomolecules for smaller gapped areas.

Energy harvesting with dielectric elastomer tubes: active and (responsive materials-based) passive approaches

Mechanical to electrical energy conversion is a well-established energy transduction approach. However, cases in which a mechanical energy source is not available call for new approaches to harvest electrical energy. In the present study, we demonstrate energy harvesting in soft dielectric elastomer (DE) tubes. Broadly, energy harvesting is obtained through inflation of the tube, electrical charging of the DE layer, and deflation, which results in a decrease in capacitance and an increase in voltage. We propose two methods to mechanically charge (or inflate) the system: (1) active, in which the tube is inflated through the application of mechanical pressure, and (2) passive, in which a passive cylindrical component placed inside the DE tube deforms radially in response to an environmental stimulus such as thermal excitation or water uptake and inflates the DE tube. To demonstrate passive charging, we consider gels as the passive component and employ well-known models with the properties of the commonly employed DE VHB 4910 to simulate the mechanical response of the system and estimate the harvested electrical energy. Our findings reveal that energy-densities in the order of ∼10–50 mJ cm–3 can be harvested. The proposed approach and the inclusion of a passive component to mechanically charge the system opens new opportunities to generate energy in environments lacking traditional mechanical energy sources.

Electrochemical evaluation and structural characterization of polythiophene surfaces modified with PbO/PbS for energy storage applications

Polythiophene (PTh) was modified with nanoparticles of lead oxide (PbO) and lead sulfide (PbS) to enhance its electrochemical performance. The surface characteristics, crystalline structure, and electrochemical behavior of the PTh/PbO/PbS material were analyzed and compared with pristine PTh. Surface modification was found to enhance the structural stability of PTh without compromising its specific capacitance. The electrochemical properties of the synthesized PTh/PbO/PbS electrode were assessed using cyclic voltammetry (CV) and AC impedance techniques in a 3 M KOH electrolyte. Specific capacitances of 245, 620, 716, and 992 F/g were achieved for PTh, PTh/PbO, PTh/PbS, and PTh/PbO/PbS, respectively, at 5 A/g. This enhancement is attributed to the synergistic effect of Pb2+ ions in the PTh/PbO/PbS electrode material. The PTh/PbO/PbS electrode in KOH exhibited average specific energy and specific power densities of 972 Wh kg−1 and 6086 W/kg, respectively, with only a 4% decrease in capacitance after 10000 cycles. The resulting PTh/PbO/PbS nanocomposite displayed highly stable and porous layered structures. This study underscores the favorable structural stability and electrochemical performance of PTh/PbO/PbS nanomaterials, positioning them as promising materials for supercapacitor applications.

Spinning of Carbon Nanofiber/Ni–Cu–S Composite Nanofibers for Supercapacitor Negative Electrodes

The preparation of composite carbon nanomaterials is one of the methods for improving the electrochemical performance of carbon-based electrode materials for supercapacitors. However, traditional preparation methods are complicated and time-consuming, and the binder also leads to an increase in impedance and a decrease in specific capacitance. Therefore, in this work, we reduced Ni-Cu nanoparticles on the surface of nitrogen-doped carbon nanofibers (CNFs) by employing an electrostatic spinning method combined with pre-oxidation and annealing treatments. At the same time, Ni-Cu nanoparticles were vulcanized to Ni–Cu–S nanoparticles without destroying the structure of the CNFs. The area-specific capacitance of the CNFs/Ni–Cu–S–300 electrode reaches 1208 mF cm−2 at a current density of 1 mA cm−2, and the electrode has a good cycling stability with a capacitance retention rate of 76.5% after 5000 cycles. As a self-supporting electrode, this electrode can avoid the problem of the poor adhesion of electrode materials and the low utilization of active materials due to the inactivity of the binder and conductive agent in conventional collector electrodes, so it has excellent potential for application.

Local outlier factor based condition monitoring for sub-module capacitors in modular multilevel converters

Modular multilevel converters (MMC) as a key technology for future power grids is rapidly developing. The failure rate of sub-module (SM) capacitors is only lower than that of power devices in MMC, so accurate evaluation of the reliability of capacitors is crucial for the safe operation of MMC. Both the increase of equivalent series resistance (ESR) and decrease of equivalent series capacitance (ESC) are features for capacitor deteriorating. ESC or ESR of the capacitor reaching to limited values indicates that the end of its lifespan and it must be replaced. Most of contemporary researches only focus on ESC or ESR. This article considering the characteristics of both ESC and ESR, proposes a method for monitoring the status of SM capacitors based on machine learning algorithm: local outlier factor (LOF). By utilizing the existing SM switching function and capacitor voltage signals within a fundamental frequency cycle in the control system of MMC, the proposed strategy can not only monitor the faulty capacitors, but also can sort the degrees of abnormal states of capacitors, and the strategy is applicable to MMC with single and multiple types of SM topologies. The proposed method is verified by the hybrid MMC model on Matlab/Simulink.

An anomalous low dose phenomenon in gamma irradiated BaTiO3-based commercial multilayer ceramic capacitors

Owing to its miniaturization and high dielectric permittivity, BaTiO3-based multilayer ceramic capacitors (MLCCs) have attracted more and more attention in recent years, and are widely used in gamma-ray environments, such as nuclear and space application. Compared to the extensively studied thermal or electrical reliability issues, the potential risks caused by irradiation have not been well understood, let alone the dielectric structure changes. Unlike the common monotonic dose-dependent trend, we found non-monotonic results in MLCCs with low dose, named as the anomalous low dose (ALD) phenomenon. That is the capacitance decreases at low gamma-ray doses, and then abnormally recovers to the initial value at high doses. Similar cases have been found in almost all the physical properties of MLCCs. Intensive characterizations help to confirm that it is the dose-dependent consistent lattice and electronic structure changes that are most likely to cause this anomalous phenomenon. In detail, the gamma irradiation induces charged defects and consequently lattice distortion, which reduces the number of domains with low-field inversion and eventually causes the capacitance decrease. This work provides a new cognition about the gamma irradiation effect of BaTiO3-based (BTO) dielectrics and commercial MLCCs based on BTO.

Insight into the scaling behavior of capacitive deionization for the removal of multiple cation components in the single-pass mode

Capacitive deionization (CDI) can effectively remove various ions in seawater and brackish water. However, due to the complex cation components in natural water, the desalination stability of CDI is challenged by cation scaling. In this study, the scaling behavior of CDI for the removal of multiple cation components in the single-pass mode was investigated. Three feed solutions containing various compositions (FS1 for Na+, FS2 for Na+/Ca2+/Mg2+, and FS3 for Na+/Ca/Mg2+/Fe3+) were tested. The results showed that the desalination stability was affected by cation components. Especially, the salt adsorption capacity for FS3 dramatically decreased from 7.16 to 3.53 mg/g over multiple cycles. Characterization demonstrated that the scaling of Ca and Mg for FS2 was slight while the scaling of Fe for FS3 was noticeable. Additionally, compared to FS2 scale, Fe significantly aggravated the scaling of Ca and Mg. The severe scaling behavior led to a decrease in specific capacitance, and an increase in charge transfer resistance and ion diffusion resistance of CDI electrodes. Finally, the correlation between scaling behavior and Faradaic reactions was comprehensively explored. The study provides insight into the scaling behavior of CDI, which is crucial for desalination stability in actual operation.

Experimental Study on the Deterioration of Nickel Cadmium Battery Based on External Characteristic Analysis

Although nickel cadmium batteries have good comprehensive performance and have been used in rail transit auxiliary power systems for a long time, battery degradation is inevitable during long-term use, which largely limits its power output capability and increases the cost of use. Unlike lithium batteries, the degradation study of nickel cadmium batteries has many shortcomings, mostly limited to a certain characteristic data for degradation prediction, and lack of systematic experimental study. Therefore, this article investigates the external characteristics of nickel cadmium battery degradation from multiple points, such as electrochemical impedance, heat production, thermal stability, gas production, etc. Through the experimental analysis, it can be seen that the degradation leads to an advance in the time of oxygen production, a decrease in the thermal stability, an increase in the heat production per unit time, an increase in the charge transfer impedance and a decrease in the interface double layer capacitance.

Optimizing the Crystallinity of a ZrO2 Thin Film Insulator for InGaZnO‐Based Metal–Insulator–Semiconductor Capacitors

AbstractThe utilization of a zirconium oxide (ZrO2) thin film as the insulator in a metal–insulator–semiconductor (MIS) capacitor to enhance the characteristics of thin‐film transistors is investigated. Although the high crystallinity of ZrO2 is favorable to achieving higher capacitance density in metal–insulator–metal capacitors with ZrO2 thin films, it decreases the capacitance with increasing applied bias in Mo/ZrO2/InGaZnO (IGZO)‐structured MIS capacitors. Through comprehensive physical, chemical, and electrical characterizations, this study investigated the mechanism underlying the decreasing capacitance with increasing the applied bias in the accumulation state of the Mo/ZrO2/IGZO‐structured MIS capacitor depending on the crystallinity of ZrO2. Furthermore, the investigation identifies the optimal crystal structure of ZrO2 thin films for IGZO‐based MIS capacitors, highlighting the importance of forming meso‐crystalline structures in high dielectric constant (k) materials to enhance the k value and mitigating the decrease in capacitance caused by the accumulated carrier loss through grain boundaries of ZrO2.

A preliminary attempt at capacitive deionization with PVA/PSS gel coating as an alternative to ion exchange membrane

ABSTRACT PVA/PSS composite gel membrane electrode for membrane capacitive deionization (MCDI) was fabricated and characterised in the present study. The composite electrode with ion exchange surface is prepared by coating glutaraldehyde cross-linked polyvinyl alcohol (PVA) composite hydrogel, with Poly (Sodium 4-Styrenesulfonate) (PSS) added into the network, on the surface of activated carbon (AC) electrode. The feasibility of the gel membrane is analyzed by rheological, swelling rates and ion exchange capacity tests. Then electrochemical test and desalination test are used to study the performance of the MCDI electrode. The results show that coating of composite hydrogel layer improved the hydrophilicity, specific capacitance and lower interfacial electron transfer resistance of the electrode. Finally, we assemble the asymmetrical CDI cell with PVA/PSS composite gel electrode and AC electrode. Compared with the AC electrode, the salt adsorption capacity of PVA6-PSS15 can reach 18.9 mg g−1 and stable charge efficiency at 73.0% at operating voltage of 1.2 V. The decrease in specific capacitance of PVA6-PSS15 after 50 cycles is 1.33%, indicating that the electrode has a good cycling life. The gel membrane coated electrode prepared by PSS provides a new idea for the development of MCDI.