Conductive Paint Research Articles

Conductive waterborne silicone acrylate emulsion/carbon nanotubes composite coatings: preparation and characterization

Common organic coatings are hardly conductive and seldom applied in electromagnetic shielding fields. Thereby, the thermoplastic conductive nanocomposites, waterborne silicon-acrylic emulsion (SAE) merged with multi-walled carbon nanotubes (MWCNTs) and silica sols (Si), were prepared via co-blending method. Compared with neat SAE, the conductivity of composite latex (5 wt.% MWCNT and 1.5 wt.% Si) was raised nearly seven orders of magnitude, and the tensile strength and Young’s modulus were enhanced to 366% and 177%, respectively. The contact angle was raised from 59° to 84°. The curing temperature was decreased by 12.8 °C. These enhancements proved that the addition of MWCNTs and silica sol could boost the electrical, mechanical, curing, heatproof and waterproof performances of SAE, which will be employed in high-property conductive paint areas, including the flexible and stretchable devices.

Conduction and switching behavior of e-beam deposited polycrystalline Nb2O5 based nano-ionic memristor for non-volatile memory applications

Investigation has been done of bipolar resistive switching mechanism of Pt/Nb2O5/Pt and Bare conductive paint (BCP)/ Nb2O5/Pt memristive devices with orthorhombic phase prepared by e-beam evaporation method. The device exhibits reproducible switching with a ratio of (Roff/Ron) of 20 or higher which is good enough in read out for practical memory devices. The device exhibits reversible switching and better consistency during the switching from a high resistance state to a low resistance state and vice versa under a low operational voltage (<±1 V) due to its controlled formation and/or annihilation of conduction path. Switching mechanism is elucidated using a model invoking drift and diffusion of oxygen vacancies for the formation and rupture of conduction path during the Set and Reset process. The as deposited Nb2O5 thin film shows itself as amorphous in nature and transferred to orthorhombic phase by post annealing at 600 °C/30 min in O2 ambient. The reliability test of memristive device stack structures has been investigated by observing the retention of 600 min and reproducible switching through endurance test of over 1000 cycles which is better than the reported structures employing single layer of Nb2O5. The device does not show any performance degradation during the test.

Nonvolatile Resistive Switching of Mn3O4 Thin Films for Flexible Electronics Applications

Introduction: We report here our success in developing a flexible RRAM stack structure by employing a low-cost method. Bare conductive commercial electric paint is used as anode against Stainless Steel (SS) foil deposited with Mn3O4 thin films forming a BCEP/Mn3O4/SS thin film stack to understand the intrinsic non-volatile resistive switching behavior of Mn3O4. Experimental: Thin film Mn3O4 is deposited on a SS (304) foil by means of potential sweep voltammetry by maintaining typical conditions. Interestingly, the pristine device is subjected to an electroforming process which exhibited a digital type bipolar resistive switching characteristics. The study of the conduction mechanism revealed that the resistive switching arises due to local effect occurring in the bulk of Mn3O4, which corresponds to the growth and annihilation of oxygen vacancy nanofilaments, and this is responsible for the change in resistance state of the RRAM between Low Resistance State (LRS) and High Resistance State (HRS) respectively. Results: In order to affirm the reliability and reproducibility of RRAM structure, the memory retention is monitored over 103 s and subsequently, the endurance test is also carried out ensuring the reproducibility over 100 cycles. Conclusion: Owing to the flexible nature of BCEP/Mn3O4/SS Foil RRAM stack structure, it is perceived to be a prime candidate for future non-volatile memory and flexible electronics applications.

Systematic Investigation from Material Characterization to Modeling of Jute-Substrate-Based Conformal Circularly Polarized Wearable Antenna

This study considers emerging trends to develop a textile-based circularly polarized (CP) conformal textile antenna on jute textile material as a natural fiber substrate due to its durability, ecofriendliness, and skin-friendly nature. The jute fabric material was subject to extensive study by scanning electron microscopy to compared it with other, related materials such as cotton and silk. Considering the infeasibility of using cotton or silk, jute textile is considered to be an effective textile substrate due to its active fiber interaction, low level of noncellulose impurities, and excellent antistatic properties. The topology of the proposed textile antenna is inspired by the tai chi symbol, where the main radiating structure has a semicircular shape and the ground structure include a similar form but complementary to the main radiating element. Industrial-grade conductive copper paint was used to achieve conducting radiating elements. The designed antenna resonates with circular polarization (CP) at 3.5 GHz, 4.9 GHz, and 5.8 GHz in the Worldwide Interoperability for Microwave Access, wireless local area network, and industrial, scientific, and medical radio bands. The variations of the resonant frequencies, axial ratios, and surface current distributions of the textile-based antenna were systematically investigated with bending at different angles to evaluate its use in body-mounted applications.

Simultaneously removal of Cr(VI) and Cd(II) from water using a flower-like primary battery nanosystem

In this study, a new flower-like primary battery nanosystem termed “Zn/CCP/ZIF-8” was prepared by depositing conductive carbon paint (CCP) and zeolitic imidazolate framework-8 (ZIF-8) on a zinc plate (Zn). Therein, CCP had good conductivity performance and adhesiveness, ZIF-8 and Zn/CCP/ZIF-8 possessed BET specific surface areas of 1909.5 and 1265.4 m2/g respectively. The results showed that the Zn/CCP/ZIF-8 nanosystem could effectively simultaneously adsorb hexavalent chromium (Cr(VI)) and bivalent cadmium (Cd(II)) from water. The system could promote the transfer of electrons from Zn to Cr(VI) and Cd(II) which were effectively reduced to trivalent chromium (Cr(III)) and cadmium (Cd), respectively. The resultant Zn/CCP/ZIF-8/Cr/Cd composite was then easily separated from water. The adsorption isotherm, kinetics, and thermodynamics of the prepared Zn/CCP/ZIF-8 for Cr(VI) and Cd(II) were investigated. An electrochemistry performance test proved that the Zn/CCP/ZIF-8 system was a primary battery. Notably, the Zn/CCP/ZIF-8 system substantially reduced the amounts of Cr(VI) and Cd(II) absorbed by zebrafish and water spinach, thus increasing food safety. The results of a rat test indicated that the Zn/CCP/ZIF-8 system possessed a high biosafety. This study provides a promising, eco-friendly, and facile method for the simultaneously treatment of Cr(VI) and Cd(II) contamination of water.

A Wearable CMOS Impedance to Frequency Sensing System for Non-Invasive Impedance Measurements.

In this paper, we demonstrate a novel non-invasive, wearable impedance sensor. The impedance sensor, using an impedance to frequency measurement, with two modes of resistance and capacitance measurement is implemented in CMOS 130nm technology. The sensor consisting of current and voltage comparators for different mode of measurement, has a low power consumption of 30 μW per channel. The sensor is demonstrated in two applications, thoracic impedance and hand gesture recognition. Thoracic impedance is based on impedance modulation through fluid accumulation. Hand gestures are detected through tissue impedance sensing. The full thoracic impedance sensing system is smaller than a credit card, low cost, and consumes 3mW which includes the sensor, transmitter, and power control unit. Data received by this sensor can be easily transferred for further processing and, eventually, detection of heart failure. The electrodes were implemented using conductive paint, and the system was validated using passive loads to represent human tissue models and test subjects. The hand gesture system operates on 600 μW with the maximum number of electrodes, and uses adhesive copper with electrical paint as electrodes.

Light-colored conductive fabric coatings using uniform ATO@TiO2 whiskers

In this work, one-dimensional conductive TiO2 whiskers coated with antimony-doped tin oxide (ATO@TiO2) were prepared with a method of hydrothermal coprecipitation. Specially, sodium hexametaphosphate (SHMP) was used as an interfacial reactor to form sufficient active groups on the surface of TiO2 whiskers, which not only increased the reaction sites, but also formed the electric double-layer structure to promote the dispersion of TiO2 whiskers in aqueous solution. Additionally, four kinds of ATO@TiO2 nanomaterials with different appearances were introduced into waterborne polyurethane (WPU) emulsion to prepare the conductive paint for the surface coating of polyester fabrics. During the process of curing reaction, ATO@TiO2 whiskers are located in the coating mold to organize a conductive network in the form of a rod-to-rod connection. Compared with particle-type ATO@TiO2, the percolation threshold was drastically decreased from 45 to 7.5 wt%, meanwhile, this conductive paint shows excellent covering performance and the whiteness is up to 83.

Fused deposition modeling fabricated PLA dielectric substrate for microstrip patch antenna

Nowadays, microstrip patch antenna finds wider usage because of its high performance, smaller size, low cost, and easy installation. The microstrip patch antennas are used in spacecraft, satellite, aircraft and wireless communication systems. However, with the conventional manufacturing technique, it is difficult to produce complicate slots in patch antenna. Hence the suitability of 3D printing for fabricating microstrip patch antenna is experimentally analysed. In this present work, Poly Lactic Acid (PLA) parts fabricated using Fused Deposition Modelling (FDM) is suggested as a substrate for microstrip patch antenna. The radiating patch and ground plane is formed on the 3D printed PLA substrate by applying conductive copper paint. The performance measures such as radiation pattern, gain and return loss of the developed 3D printed substrate are analysed by comparing the experimental and simulation results. With PLA substrate, double band is observed at 5.24 GHz and it corresponds to Wireless Local-area Network (WLAN) and C band. Further, PLA dielectric substrate has the ability to produce higher gain above 2 dB. The gain plots showed a good equivalence between the measured and simulated results. With the achieved results, it can be inferred that FDM printed PLA parts can be used as a substrate for micro strip patch antenna.

Three-dimensional Printing of Supercapacitors based on Different Electrodes

Abstract A fused deposition modeling (FDM) printing machine and a paste extrusion system were integrated, and supercapacitor samples were fabricated using a combination of two three-dimensional (3D) printing techniques. The FDM provided a simple method for creating a frame of electric double layer capacitor (EDLC) samples. The paste extrusion system offered the possibility of depositing different materials to complete the functions of the EDLC samples. A combination of these two 3D printing methods offered one continuous manufacturing process with a high accuracy of manufacturing. Different materials were used to build current collectors and electrodes. Silver and carbon conductive paints were used as current collector materials. Different electrode materials based on activated carbon (AC), carbon conductive paint, and their combination were prepared as three different slurries and deposited to form the electrodes of EDLC samples. The results showed that silver conductive paint was a suitable material for constructing current collectors, and carbon conductive paint mixed with AC was highly effective for use as an electrode material for supercapacitors.

Heterogeneous Electrofreezing Triggered by CO2 on Pyroelectric Crystals: Qualitatively Different Icing on Hydrophilic and Hydrophobic Surfaces

AbstractBy performing icing experiments on hydrophilic and hydrophobic surfaces of pyroelectric amino acids and on the x‐cut faces of LiTaO3, we discovered that the effect of electrofreezing of super cooled water is triggered by ions of carbonic acid. During the cooling of the hydrophilic pyroelectric crystals, a continuous water layer is created between the charged hemihedral faces, as confirmed by impedance measurements. As a result, a current of carbonic acid ions, produced by dissolved environmental CO2, flows through the wetted layer towards the hemihedral faces and elevates the icing temperature. This proposed mechanism is based on the following: (i) on hydrophilic surfaces, water with dissolved CO2 (pH 4) freezes at higher temperatures than pure water of pH 7. (ii) In the absence of the ionic current, achieved by linking the two hemihedral faces of hydrophilic crystals by a conductive paint, water of the two pH levels freeze at the same temperature. (iii) On hydrophobic crystals with similar pyroelectric coefficients, where there is no continuous wetted layer, no electrofreezing effect is observed.

Heterogeneous Electrofreezing Triggered by CO2 on Pyroelectric Crystals: Qualitatively Different Icing on Hydrophilic and Hydrophobic Surfaces.

By performing icing experiments on hydrophilic and hydrophobic surfaces of pyroelectric amino acids and on the x-cut faces of LiTaO3 , we discovered that the effect of electrofreezing of super cooled water is triggered by ions of carbonic acid. During the cooling of the hydrophilic pyroelectric crystals, a continuous water layer is created between the charged hemihedral faces, as confirmed by impedance measurements. As a result, a current of carbonic acid ions, produced by dissolved environmental CO2 , flows through the wetted layer towards the hemihedral faces and elevates the icing temperature. This proposed mechanism is based on the following: (i) on hydrophilic surfaces, water with dissolved CO2 (pH 4) freezes at higher temperatures than pure water of pH 7. (ii) In the absence of the ionic current, achieved by linking the two hemihedral faces of hydrophilic crystals by a conductive paint, water of the two pH levels freeze at the same temperature. (iii) On hydrophobic crystals with similar pyroelectric coefficients, where there is no continuous wetted layer, no electrofreezing effect is observed.

Design and Initial Testing of an Affordable and Accessible Smart Compression Garment to Measure Physical Activity Using Conductive Paint Stretch Sensors

Motion capture and the measurement of physical activity are common practices in the fields of physical therapy, sports medicine, biomechanics, and kinesiology. The data collected by these systems can be very important to understand how someone is recovering or how effective various assistive devices may be. Traditional motion capture systems are very expensive and only allow for data collection to be performed in a lab environment. In our previous research, we have tested the validity of a novel stitched stretch sensor using conductive thread. This paper furthers that research by validating a smart compression garment with integrated conductive paint stretch sensors to measure movement. These sensors are very inexpensive to fabricate and, when paired with an open-sourced wireless microcontroller, can enable a more affordable, accessible, and comfortable form of motion capture. A wearable garment like the one tested in this study could allow us to understand how meaningful, functional activities are performed in a natural setting.

Eco-friendly biowaste-derived graphitic carbon as black pigment for conductive paint

In this study, we developed a bio-inspired, eco-friendly, and cost-effective conductive paint (CP). Conventionally, carbon-based black pigment (CBP) was derived from cow dung, which is an eco-friendly, easily available, and inexpensive biowaste material. Subsequently, CP has been prepared using as-prepared CBP. Herein, for the first time, we used CBP as a conductive pigment that was mixed with an air-dried alkyd resin as a binder for paint formulation. As the conductive pigment, the CBP interconnected in the paint matrix by forming percolation pathways; this resulted in excellent conductive behavior of the as-prepared CP. The intermolecular interaction between the alkyd resin and the conductive pigment resulted in a CP that exhibited excellent conductivity as well as energy storage ability. The sheet resistance of the CP, studied using a four-probe resistivity method, was ∼8.61 × 10−7 Ω sq-1. The biowaste-derived CP also exhibited a high specific capacitance of 216 F g-1 and a high energy density of 24 Wh kg-1 at a current density of 1 A g-1. The main advantage of our prepared CP is better conductivity than that of carbon black, graphite, graphene, and carbon nanotube. As a result, the prepared CP may have applications in several fields, such as antistatic coatings, energy storage, electromagnetic shielding, and electronic circuits.

High-performance electric double-layer capacitor fabricated with nanostructured carbon black-paint pigment as an electrode

Engineering the microstructure of the carbonaceous materials is a promising strategy to enhance the capacitive performance of supercapacitors. In this work, nanostructured Black Pearl (1500 BP) carbon which is a conductive carbon being commercially used in printing rolls, conductive packaging, conductive paints, etc. is analyzed for its feasibility as an electrode material for Electric Double-Layer Capacitors (EDLCs). To achieve that commercial Black Pearl (BP), carbon is treated with mild acid H3PO4 to remove the impurities and enhance the active sites by regulating the growth of agglomerates and creating micropores in the nano-pigments. Generally, the coalescence of nanoparticles owing to their intrinsic surface energy has tendency to create voids of different sizes that act like meso/micropores facilitating the diffusion of ions. The electrochemical performance of BP carbon before and after chemical activation is investigated in aqueous (H2SO4, KOH and KCl) and a non-aqueous electrolyte (1 M TEMABF4 in acetonitrile) environment employing different electrochemical techniques such as Cyclic Voltammetry (CV), Galvanostatic charge/discharge (GCD) and Electrochemical Impendence Spectroscopy (EIS). The chemically activated BP carbon delivers the highest specific capacitance of ∼156 F g−1 in an aqueous electrolyte, 6 M KOH. The highest specific power, ~ 15.3 kW kg−1 and specific energy, 14.6 Wh kg−1 are obtained with a symmetric capacitor employing non-aqueous electrolyte because of its high working potential, 2.5 V.

A Test Device for Microalgal Antifouling Using Fluctuating pH Values on Conductive Paints

Due to the current dependence on biocidal antifouling coatings for biofouling control, there is a continuing international challenge to develop more environmentally acceptable antifouling systems. Fluctuating the pH values on paint surfaces is one of these approaches. We developed an antifouling test device to investigate algal biofilms on conductive paints by using a flume with electrochemically working test panels and subsequent confocal laser scanning microscopy (CLSM) of biofilms. By employing a pole reversal of direct current, fluctuating pH values on the paint surface were generated. As a consequence of the resulting pH stress, colonization of the paint surface by diatoms decreased substantially. The density of biofilm algae decreased with increasing pH fluctuations. However, breaks between electrochemical treatments should not exceed one hour. Overall, we established an experimental setup for testing the antifouling capabilities of electrodes based on conductive paints, which could be used for further development of these varnishes.

Prevention of copper corrosion on post-FIB wet stained sample using UV charge-neutralization method

This paper presents the study of various charge neutralization methods to prevent copper corrosion on post-FIB wet stained sample. Conventional fast and economic wet staining on post-FIB copper processed sample can sometimes cause unwanted artifact such as copper corrosion due to build-up of charges on non-grounded, long copper interconnect structures during FIB milling. Some charge neutralization methods such as probe-pin grounding, conductive paint application and UV treatment were investigated on an ET structure. The recommended method, using UV treatment, is applied to the die area on a bulk Si wafer and on a SOI (Si-on-insulator) wafer to compare the effect of this method in preventing the copper corrosion effect.

Fabrication of anode electrode by a novel acrylic based graphite paint on stainless steel mesh and investigating biofilm effect on electrochemical behavior of anode in a single chamber microbial fuel cell

Microbial fuel cell (MFC) is a novel green technology that converts the chemical energy of biodegradable wastes into bioelectricity. One of the greatest challenges in making MFC a scalable and cost-effective technology is electrode material and design. Conductive inks and paints based on carbon materials are attractive options to modify the surface of electrodes. By preparing these paints in a simple way that their raw materials are easily found, the performance of electrodes such as stainless steel mesh (SSM) can be improved in the field of power generation. So, low-cost high performance electrodes can be produced. Despite various binders for making graphite paints (GPs), we used acrylic binder to make the graphite conductive paint by a simple cost-effective process for the first time to the best of our knowledge. By studying the electrochemical characteristics of acrylic-based GP, it was found that the acrylic has high stability in aqueous environments and excellent adhesion properties to hold graphite particles together. As a result, the surface of the SSM was modified using acrylic-based GP and applied as low cost anode electrode with sinusoidal geometry in single chamber MFC (SCMFC). The biofilm formation and its effect on the novel anode were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) during 5 weeks of operation in SCMFC. Then, six individual circuits were created by connecting each anode electrode to an air cathode. The membrane-less SCMFC was able to generate a maximum power density of 463.88 mW/m3 at 1991 mA/m3 using only one of these circuits.

Low cost Raman sample substrates from conductive silver paint smear for Raman spectroscopic screening of metabolic diseases in whole blood

This work reports on a low cost, simple to prepare and chemically stable Raman substrates based on conductive silver paint smear. The substrates were characterized Raman spectroscopically and were found to be chemically stable within the first seven days when kept at room temperature as the spectroscopic profiles were unchanged. The substrates also suppressed the background signals emanating from glass centered around 750 cm−1 and 1370 cm−1 seen with 785 nm excitation and had negligible influence on Raman spectral profiles of rat’s blood samples applied onto them. The Raman spectral profiles of blood samples applied onto the substrates were found to be enhanced by a factor of 1.7 compared to those of thick blood smears on a clean microscope glass slide. The increased local field between the gaps formed by adjacent micron-sized silver solids in the paint smear were attributed to the observed intense signals observed from the blood samples applied onto them. The substrates were tried on Raman spectroscopic differentiation between blood from obese and normal; diabetic and normal Sprague Dawley rats. The prominent bands associated with fructose (638 and 812 cm−1), glucose (1127 cm−1) and branched chain amino acids (1033, 1217 and 1318 cm−1) were observed to vary in terms of intensity between the un-healthy (obese and diabetic) and healthy (normal) rats. The results reported here on the use of the easy to prepare, low cost Raman substrates have the potential of making surface-enhanced Raman spectroscopy accessible to less resourced laboratories in developing countries. The substrates can be applied in rapid Raman spectroscopic screening of various metabolic diseases.

Paper Strip and Ceramic Potentiometric Platforms Modified with Nano-Sized Polyaniline (PANi) for Static and Hydrodynamic Monitoring of Chromium in Industrial Samples.

Screen-printed membrane sensors based on the use of paper and ceramic substrates are fabricated, characterized, and used for rapid batch and continuous monitoring of CrIII in the form of CrO42− in some industrial products and wastewater samples. Strips of paper and ceramic platforms (15 × 5 mm) were covered with conductive carbon paint and then modified with polyaniline (PANI) film, to act as an ion-to-electron transducer, followed by a drop casting of plasticized poly (vinyl chloride) (PVC) Rhodamine-B chromate membrane as a recognition sensing material. In a 5.0 mmol L−1 Trizma buffer solution of pH ~8, the fabricated paper and ceramic based membrane sensors exhibited a near Nernstian response for CrVI ion with slopes of −29.7 ± 0.5 and −28.6 ± 0.3 mV decade−1, limit of detection 2.5 × 10−5 and 2.4 × 10−6 mol L−1 (1.3–0.12 µg mL−1), and linear concentration range 7.5 × 10−3–5.0 × 10−5 and 7.5 × 10−3–1.0 × 10−5 mol L−1 (390-0.5 µg mL−1), respectively. Both sensors exhibited fast and stable potentiometric response, excellent reproducibility, and good selectivity with respect to a number of common foreign inorganic species. Impedance spectroscopy and chronopotentiometry data revealed a small resistance and a larger double layer capacitance due to the presence of the intermediate polyaniline (PAN) conductive layer. Furthermore, the formation of a water layer between the ion selective membrane (ISM) and the underlying conductor polymer and between the conducting polymer and the carbon conducting surface was greatly reduced. The developed disposable solid-contact potentiometric sensors offer the advantages of simple design, long term potential stability, flexibility, miniaturization ability, short conditioning time, and cost effectiveness that enable mass production. The sensors were successfully used for static and hydrodynamic measurements of total chromium in some leather tanning wastewater and nickel-chrome alloy samples. The results compare favorably with data obtained by atomic absorption spectrometry.

Investigation on heat transfer enhancement of conventional and staggered fin solar air heater coated with CNT-black paint-an experimental approach.

The present study aims at a detailed experimental study of a passive-type solar air heater (SAH) on the effect of coating the absorber plate with higher thermal conductive black paint under forced circulation method and studied under the climatic conditions of Chennai. Furthermore, to enhance the thermal performance index of conventional SAH, additional enhancement such as coating and staggered fins are fixed to the absorber plate of duct which simultaneously increases the turbulent intensity, kinetic energy to enhance the temperature of outlet air. Comparisons are made with a solar air heater without coating and staggered fin in order to assess the thermal performance. Experiments were conducted on a continuous basis and the flow rates of air flowing through the duct are varied. Experimental results revealed that the effect of coating improved the plate temperature to a maximum of 102°C while the modified SAH coated with ordinary black paint and staggered fin arrangement is found as 95°C for the flow rate of mf = 0.03kg/s. The difference in temperature between exit and inlet of conventional SAH with coating alone is found as 13.09°C at a flow rate of mf = 0.03kg/s whereas the average thermal efficiency is found as 22.3%. Similarly, increasing the mass flow rate from 0.13 to 0.22kg/s has no significant improvement in average daily thermal efficiency, whereas the temperature difference decreases. The coating of absorber plate with higher thermal conductivity paint and increased turbulence created between the duct by using staggered fin improved the temperature of exit air by 63, 64, 38 and 35% for air flow rates of 0.03, 0.04, 0.13 and 0.22kg/s respectively. On a flat absorber with coating, the average increase in temperature is found at 6.3% compared to that of SAH coated with ordinary black paint. The hourly thermal efficiency of the conventional type SAH with coating exhibited an enhancement of about 5% in thermal efficiency as compared to that of conventional type with black paint coating alone for the same climatic condition, whereas the thermal efficiency of staggered fin SAH with coating alone is enhanced by 7.5%. With staggered fin arrangement in the absorber plate, heat absorption by the air is increased with CNT-coated absorber and excessive turbulence produced by the fins enhanced the average temperature difference from 13.5 to 20.3°C. The cost per unit kW of conventional type SAH with CNT-doped black paint reduced from 0.01754 $ to 0.00832 $/kW while varying the flow rate from 0.031 to 0.22kg/s.