Sie können Operatoren mit Ihrer Suchanfrage kombinieren, um diese noch präziser einzugrenzen. Klicken Sie auf den Suchoperator, um eine Erklärung seiner Funktionsweise anzuzeigen.
Findet Dokumente, in denen beide Begriffe in beliebiger Reihenfolge innerhalb von maximal n Worten zueinander stehen. Empfehlung: Wählen Sie zwischen 15 und 30 als maximale Wortanzahl (z.B. NEAR(hybrid, antrieb, 20)).
Findet Dokumente, in denen der Begriff in Wortvarianten vorkommt, wobei diese VOR, HINTER oder VOR und HINTER dem Suchbegriff anschließen können (z.B., leichtbau*, *leichtbau, *leichtbau*).
Der Artikel stellt ein bahnbrechendes mikropillar-fähiges Mikrogerät für akustische Wellen (μPAW) vor, das für eine präzise Viskositätsmessung in Echtzeit entwickelt wurde. Dieses innovative Gerät, das mittels thermischer Nanoimprinting-Lithographie hergestellt wird, erhöht die Empfindlichkeit traditioneller Quarzkristall-Mikrowaagen (QCM) um Größenordnungen. Das in eine mikrofluidische Plattform integrierte Gerät μPAW stellt sein Potenzial durch Experimente mit Saccharose-Lösungen unter Beweis und zeigt dabei eine hohe Empfindlichkeit und geringe Nachweisgrenzen. Die Studie stellt auch ein theoretisches Modell zum Verständnis des Funktionsprinzips des μPAW-Geräts in viskosen Lösungen vor und hebt seine überlegene Leistung im Vergleich zu konventionellen Methoden hervor. Diese Forschung ebnet den Weg für fortschrittliche Viskositätsmessanwendungen in verschiedenen Branchen, darunter Pharmazeutika, Nahrungsmittel und biomedizinische Diagnostik.
KI-Generiert
Diese Zusammenfassung des Fachinhalts wurde mit Hilfe von KI generiert.
Abstract
Viscosity measurement has recently captured considerable attention due to its wide range of applications in fields such as pharmacy, food industry, cosmetic industry, and biomedical diagnostics. Acoustic wave sensors such as quartz crystal microbalance (QCM) are well-known mass sensors that also show their capability in measuring liquid viscosity. However, the challenges for QCM-based viscosity measurement devices lie in their low sensitivity and unstable response. Herein, we report an ultrasensitive micropillar-enabled acoustic wave (μPAW) viscometer by fabricating well-defined polymethyl methacrylate (PMMA) micropillars on a QCM substrate to achieve ultrahigh sensitivity for liquid viscosity with a stable response thanks to a unique vibration coupling between the micropillar and QCM substrate. The μPAW based viscometer shows a 20-fold improvement in the measurement sensitivity over traditional QCM viscometers and achieved an excellent limit of detection (LOD) while measuring the viscosity of sucrose liquid as low as 0.054 wt%. The microdevice developed in this work is a promising tool for the viscosity measurement of liquids.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
1 Introduction
Viscosity is one of the fundamental properties of liquids and gases. Viscosity measurement has recently captured considerable attention due to its wide range of applications in fields such as pharmacy (Puneeth et al. 2021), food industry (Cullen et al. 2000), cosmetic industry (Tadros 1992), and biomedical diagnostics (Vahid et al. 2019). For example, the viscosity of the drug should be comparable to that of blood in drug delivery applications (Akyazi et al. 2018). In addition, viscosity is an important parameter in biomedical diagnostics for biofluids such as urine (Inman et al. 2013) and saliva (Farsaeivahid et al. 2022). Similarly, the food industry applies viscosity to ensure that the flow rate in pipes is sufficient to fill the packets (Tabilo-Munizaga and Barbosa-Cánovas 2005). In addition, it is crucial to develop a device capable of measuring and analyzing viscosity with high precision while requiring a small sample volume (microliter or less) (Arosio et al. 2016).
The elementary viscosity measurement relies on pouring a fluid and calculating its time to empty or fill a vessel. Traditional viscometers are classified into four broad categories: U-tube (Grattoni et al. 1993), falling/rising objects (Brizard et al. 2005), rotational (Cullen et al. 2003) and vibrational viscometers (Yabuno 2021). U-tube Viscometers include a U-shaped glass tube, where the viscosity is determined by the time required for the fluid to fill the tube. The working principle of the falling ball viscometer is based on stokes’ law and the measurement of the time required for the object to fall due to the fluid's resistance. Rotational viscometers evaluate the viscosity by turning a spindle in the solution and measuring the required torque. Vibrational viscometers, which are the most common among traditional viscometers, determine viscosity based on the induced viscous drag on a vibrating blade. Recently, microfluidic channels and devices have been developed as a result of advancements in micro-nanofabrication technologies. Microfluidic viscometers are classified into five broad categories: Pressure sensing (Pipe et al. 2008), Flow rate sensing (Solomon et al. 2016), Microfluidic Comparator (Kang et al. 2010), Droplet-based (Li et al. 2017) and Surface Tension viscometers (Srivastava and Burns 2006).
Anzeige
Quartz crystal microbalance (QCM) device is a bulk acoustic wave (BAW) piezoelectric sensor oscillating in thickness-shear mode (TSM) (Ji et al. 2021). The sensing mechanism of a QCM is based on detecting the resonance frequency shift resulting from surface mass loading and near-surface liquid layer viscoelastic properties. The typical sensing resolution of a QCM device operating in a gas phase is approximately 1 ng/cm2 per Hz, while the reliable measurement for a mass accumulation is up to 100 µg/cm2 (O’sullivan and Guilbault 1999). The sensing capacity of QCM devices can be versatile as the sensor surface can be easily functionalized with chemical sensing materials. In addition, the QCMs can operate in liquids where part of the shear vibration is transferred to the liquid, causing elastic energy dissipation in the surrounding liquid medium (Yang and Thompson 1993; Ash et al. 2003). This interaction results in the frequency shift, which is described by the Kanazawa and Gordon model and given by Kanazawa and Gordon (1985):
where \({\rho }_{L}\) is the density and \({\eta }_{L}\) is the viscosity of the fluid. Zq and fo represent the mechanical impedance and the natural frequency of the quartz substrate. As can be seen, the change in \({\rho }_{L}{\eta }_{L}\) leads to the frequency shift (Δf). For example, Table 1 presents the frequency shifts of the 10 MHz QCM in responding to the viscosity of the aqueous solutions (Wang et al. 2014a).
Table 1
Frequency shifts of bare QCM (10 MHz) for different solutions
Solution
Frequency shift (Hz)
Measured Avg. Viscosity (cP)
NaCl (30 wt%)
133
1.5563
HCl (30 wt%)
97
1.4829
KCl (30 wt%)
47
0.952
Recently, a novel micropillar-enhanced acoustic wave (μPAW) was enabled by fabricating micropillars on a QCM substrate, resulting in orders of magnitude higher mass sensitivity than traditional QCM devices, thanks to a unique coupling between micropillars and QCM (Wang et al. 2014a; Esfahani and Sun 2023).
For instance, the μPAW device improved the mass sensitivity of conventional QCM by three times in detecting acrylic acid grafting and twenty times in measuring bovine serum albumin (BSA) adsorption (Wang et al. 2015; Esmaeilzadeh et al. 2019). In addition, the μPAW devices was used for humidity detection (Wang et al. 2014b). The results showed that the μPAW can enhance resonant frequency shift up to 27 times compared to conventional film based QCM. Su et al. evaluated ligand-analyte binding interactions between anti-human immunoglobulin G (anti hIgG) and human immunoglobulin G (hIgG) using μPAW devices (Su et al. 2018). The μPAW devices demonstrated a detection limit of 80 nM.
Although μPAW devices have been used to detect adsorbed mass on the surface, little study has been conducted to measure the effect of the near-surface liquid layer. This study reports the effect of liquid viscosity on μPAW devices, exploring the potential of μPAW for viscosity measurement. The paper starts with fabricating a PMMA micropillar array on a QCM using thermal Nanoimprinting Lithography (T-NIL). Then a microfluidic μPAW device is developed by integrating the μPAW sensor with a commercial Discovery-Q (Invetrometrix) platform. The sucrose solutions with different viscosities are measured using the developed μPAW system, and sensitivity enhancement analysis for four micropillar heights is performed. At last, a theoretical model based on the cantilever beam analysis is presented to understand the working principle of μPAW for viscosity measurement.
Anzeige
2 Mathematical model
In the case of μPAW operating in air or vacuum medium, the damping effect can be neglected and the resonance frequency can be simply analyzed by solving two mass-spring systems (Wang et al. 2014c). The quartz can be considered as the main resonator (mq, kq) and the micropillar as the second resonator (mp, kp). However, the dynamic response of the μPAW system becomes more complicated when the interacting medium is liquid (Wang et al. 2015). For a traditional QCM viscometer device operating in a liquid, the oscillation of quartz results in a shear wave in a thin liquid layer of thickness of nanometer-scale (decay length, δ) near its surface. The frequency response of QCM can be determined by assuming an effective liquid mass layer moving with the QCM surface (Kanazawa and Gordon 1985). The decay length and effective mass are expressed as (Kanazawa and Gordon 1985):
where \(\Delta m\) is the effective mass and \(A\) is the sensing area. Different from traditional QCM, the micropillars of the μPAW device can be analyzed as a microscale cantilever beam vibrating in a liquid where the angular frequency (ω) of micropillar operating in viscous solution is expressed as (see Supplementary Materials):
where E is the young modulus, I the momentum of inertia, H is the height, W is the width, and \(\dot{m}\) is the mass per unit length of the micropillar. \({\gamma }_{1}\) is the real part of induced hydrodynamic loading on rectangular micropillars. The analytical approximation of \({\gamma }_{1}\) on rectangular micropillars is expressed as (Wang et al. 2014c):
where \({a}_{1}\) and \({a}_{2}\) two constants with values of 1.0553 and 3.7997 (Gupta 2014). The value of \(\beta\) can be found by solving the following equation (Su et al. 2019):
\({m}_{t}\) is an additional liquid layer moving at the tip of the micropillar and L is the total length of the micropillar. As a result, the resonant frequency of micropillars in a solution can be calculated by solving Eqs. (4–7) concurrently.
At the same time, the frequency response of μPAW can be estimated from the two-degree-of-freedom systems analysis with additional effective masses resulting from the induced hydrodynamic loading (\(\Delta {m}_{p}\)) on the QCM and micropillars (see Fig. 1). The quartz substrate is treated as the primary resonator with effective mass (\({m}_{q,eff}={m}_{q}+\Delta {m}_{q}\)) and force constant \({k}_{q}\) and the micropillar as the second resonator with effective mass (\({m}_{p,eff}={m}_{p}+\Delta {m}_{p}\)) and force constant \({k}_{p}\). As a result, the resonant frequency of the μPAW sensor can be obtained by solving:
Fig. 1
Modified two-degree-of-freedom model with additional effective masses for μPAW in a viscous solution
Therefore, the coupled resonance frequencies of μPAW sensors with varying micropillar heights are predicted by solving Eqs. (2)–(9).
3 Experimental study
3.1 Materials and devices
QCM substrates and PMMA were purchased from Fortiming Corp. (Marlboro, MA) and MicroChem Corp. (Westborough, MA). Sucrose (99 wt%) and ultrapure DI water were obtained from Innovating Science (Alden Chem) and Mili-Q plus system (MiliporeSigma), respectively. The syringe pump, syringe, and tubes were purchased from KdScientific (Holliston, MA), BD (Franklin Lakes, NJ), and Cole-Parmer (Vernon Hills, IL). The hot plate and electronic scale (PM-100, resolution: 0.001g) were purchased from Barnstead Thermolyne Corp. (Ramsey, MN) and Intelligent Weighing Technology (Port Townsend, WA). A frequency measurement system (Discovery-Q) was purchased from Invitrometrix (Lowell, MA). The flow cell of the μPAW system was fabricated by soft lithography. SYLGARD™ 184 Silicone Elastomer Kit was purchased from Dow Inc. (Midland, MI). Photolithography, Thermal Nanoimprinting Lithography (T-NIL), and Scanning Electron Microscope (SEM) were performed in Nanofabrication Lab in Core Research Facilities at the University of Massachusetts Lowell.
3.2 Micropillar fabrication
The fabrication process of PMMA micropillar for the μPAW consists of four sequential steps (Fig. 2) (Wang et al. 2014a; Esmaeilzadeh et al. 2021): (A) preparation of SU-8 mother mold; (B) replica of polydimethylsiloxane (PDMS) transfer mold; (C) filling PDMS mold with PMMA by spin coating; (D) thermal nanoimprinting lithography (T-NIL) to fabricate PMMA micropillars on QCM. After nanoimprinting, a thin residual layer (~ 3 µm) was produced between micropillars and the QCM substrate. In addition, a QCM sensor having a PMMA residual layer of the same thickness (~ 3 µm) (QCM-F) was fabricated for the purpose of comparison. The micropillars used in this study have a square cross-section with a 10 µm diameter and a 21 µm center-to-center spacing.
Fig. 2
Flow chart of fabricating PMMA micropillars on QCM quartz substrate
The PMMA pillars were characterized using a field emission scanning electron microscope (FE-SEM) and the SEM images are illustrated in Fig. 3. As can be seen, the well-defined PMMA micropillar structures were successfully transferred onto the QCM surface with a thin residual layer by the T-NIL process.
Fig. 3
SEM images of PMMA micropillars with heights of a 6.4 μm, b 10.3 μm, c 13.9 μm, and d 18.1 μm
The flow cell unit of the microfluidic μPAW device includes four sensor wells, which are electrically connected to the Discovery-Q platform underneath. Well-known softlithography was employed to fabricate the flow cell unit, where the mold of the flow cell structure was designed in SolidWorks and then printed using a 3D printer (Ultimaker 3). Figure 4a illustrates the exploded-view of the μPAW system, which consists of an electronic oscillator circuit board, interface plate, O-rings, μPAW sensors, flow cell, and cover plate (stainless plate). After micropillars are fabricated on the quartz plate, the sensors are gently placed on the top of conducting O-rings in the sensor wells of the flow cell (Fig. 4b). Then PDMS flow cell is pressed on top of the μPAW sensor and sandwiched between the cover plate and the oscillator circuit board of the Discovery-Q system. The electrical signal of the sensors is transmitted to the DAQ unit of the system and analyzed by the in-house software for display and analysis. The metallic cover plate is used to maintain the surface flatness of the PDMS flow cell and prevent leakage using screw-tightening.
Fig. 4
a Exploded view of the μPAW device assembly and b schematic of the flow cell; c actual μPAW device
Sucrose solutions with different concentrations (0.2–50 wt%) were prepared by adding sucrose.
powder to a glass vial (20 ml) on an electronic scale and then adding DI water into the vial. The vial was heated on a hotplate and stirred with a magnetic stirrer at 60 °C for 30 min, and cooled down to room temperature. The experimental setup for carrying out the test consists of the μPAW system, syringe pump, solution containers, and data acquisition (DAQ) components (Fig. 5). The experimental procedure is as follows: (1) DI water is pumped into the sensor well, and the frequency response of sensors is recorded to obtain the baseline; (2) sucrose solutions at different concentrations are driven into the well, and the response frequencies are recorded. The μPAW device was rinsed with DI water and followed by blowing nitrogen gas to dry to remove the residual after each measurement.
Fig. 5
Experimental setup for measuring viscosity using μPAW devices
All the experiments in this study were conducted at well-controlled room temperature (20 °C) to exclude the unreliable results induced by temperature variation of the solutions. It is worth noting that all the experiments were repeated three times to ensure the repeatability of the measurement results.
4 Results and discussion
4.1 Viscosity measurement of QCM-F
The Kanazawa-Gordon equation indicates (Eq. (1)) that the frequency shift of a traditional QCM is linearly related to the density–viscosity of the Newtonian solution as (Kanazawa and Gordon 1985):
$$\Delta f\sim \sqrt{{\rho }_{L}{\mu }_{L}}$$
(10)
Figure 6 presents the frequency shift of conventional QCM-F in the stationary sucrose solutions under different concentrations with respect to \(\sqrt{{\rho }_{L}{\mu }_{L}}\). As can be seen, the frequency shifts between the experimental measurements agree well with the predictions from the Kanazawa-Gordon equation (R2 = 0.998). It is worth noting that the residual layer (~ 3 µm) is so thin that the effect of the layer on the sensor’s sensitivity is negligible (Su et al. 2018). In addition, the results indicate that the effect of particle adsorption on the PMMA surface is negligible.
Fig. 6
Comparison of experimental results of QCM-F and Bare QCM with the prediction of the Kanazawa-Gordon model
Figure 7 presents the responses of μPAW sensors (pillar heights: 6.4 mm, 10.3 mm, 13.9 mm, and 18.1 mm) and QCM-F sensors to sucrose solutions with a concentration range of 10 to 50 wt%. The viscosity and density data of sucrose solutions corresponding to these concentrations are shown in Table 2 (Swindells et al. 1958). As can be seen, all the μPAW sensors show much higher frequency shifts toward the variations of sucrose solution properties (viscosity and density) than the QCM-F. For instance, QCM-F shows a maximum frequency shift of 11 kHz at 50 wt% sucrose solution, while the shifts of μPAW with a micropillar height of 13.9 mm reached 102 kHz. On the other hand, we also notice that the noise level of the 13.9 mm sensor is higher for the 50 wt% sucrose solution. This is believed to be caused by the low quality factor (Q-factor) and damping of the μPAW near the critical height.
Fig. 7
a Real-time resonance frequency responses of μPAW and QCM-F sensors to DI water (I) and sucrose solutions of concentrations of 10 wt% (II), 20 wt% (III), 30 wt% (IV), 40 wt% (V), and 50 wt% (VI) and b frequency shift as a function of sucrose concentration
The viscosity and density of sucrose solution (Swindells et al. 1958)
Concentration (wt%)
Viscosity (cP)
Density (kg/m3)
10
1.186
1038
20
1.727
1081
30
2.831
1127
40
5.474
1176
50
13.706
1230
The response of μPAW sensors is prone to the effect of nonspecific physical adsorption of particles on the surface. To exclude the impact of particle attachment, a control experiment based on the steady flow (100 μl/min) is conducted for the sensor with a micropillar height of 18.1 mm (Fig. 8a). In this experiment, DI water is injected into the flow cell to obtain the baseline. The sucrose solutions (10–50 wt%) are then flowed through the sensors, and the resonance frequency of μPAW sensors is recorded. At last, DI water is driven to flow over the sensor surface again. It is clear that if there exists a resonant frequency difference between the first and second DI water flows, some particles in the sucrose solutions must attach to the μPAW sensor surface. Figure 8a shows that the frequency shift of the μPAW sensor returned to baseline, which indicates that the adsorption of the sucrose particles is negligible. The observed frequency shift is entirely due to the change in solution properties. Figure 8b reports the comparison of the frequency shift of the μPAW (18.1 mm) in steady-state flow conditions with those of μPAW in a stagnant state. It is clear that the measurement of μPAW is not affected by the flow field conditions since viscosity is a fluid property and is not dependent on the flow condition.
Fig. 8
a Real-time resonance frequency responses of μPAW (micropillar height: 18.1 μm) in the steady-state flow of sucrose solutions at concentrations of 10 wt%, 20 wt%, 30 wt%, 40 wt%, and 50 wt%, and b comparison of frequency shifts of μPAW operating in stagnant and steady-state flow conditions
The LOD of μPAW devices was determined by evaluating the response of the sensor at various concentrations near the LOD value and constructing a linear calibration curve (Loock and Wentzell 2012). A series of experiments are conducted to determine the response of QCM-F and μPAW in sucrose solutions with concentrations ranging from 0.2 to 1.2 wt%, and the results are shown in Fig. 9.
Fig. 9
a Real-time frequency responses of μPAW and QCM-F sensors to DI water (I) and sucrose solutions of concentrations of 0.2 wt% (II), 0.4 wt% (III), 0.6 wt% (IV), 0.8 wt% (V), 1.0 wt% (VI) and 1.2 wt% (VII) and b frequency shift as a function of sucrose concentration
The results show that as sucrose concentration decreases, the frequency shifts of the μPAW and QCM-F decrease accordingly. Both μPAW and QCM-F sensors are capable of detecting variations of the solution properties up to 1.2 wt%. The μPAW with 13.9 μm micropillar height shows a frequency shift of 2657 Hz for the 1.2 wt% sucrose concentration, compared to only 32 Hz measured from QCM-F (Fig. 9b). The μPAW is able to measure the variation at sucrose concentration as low as 0.2 wt%, while there is almost no response from QCM-F for sucrose concentration below 0.6 wt%. The obtained analytical LODs based on the linear calibration curve for μPAW and QCM-F sensors are shown in Table 3. Decreasing LOD is achieved by embedding micropillars with QCM compared to QCM-F. It is obtained that the μPAW with 13.9 μm micropillar height has a LOD of 0.054 wt%, compared to 0.54 wt% measured from QCM-F. In addition, μPAW sensors close to critical height can achieve minimum LOD compared to the μPAW sensors out of the ultra-sensitive zone.
Table 3
LOD of μPAW and QCM-F sensors
Sensor
LOD (wt%)
Viscosity (cP)
QCM-F
0.54
1.014
μPAW, hp 6.4 μm
0.069
1.0018
μPAW, hp 10.3 μm
0.061
1.0016
μPAW, hp 13.9 μm
0.054
1.0014
μPAW, hp 18.1 μm
0.060
1.0016
4.4 Comparison with model prediction
To validate the developed model in Sects. 2–3 (Eqs. (2–9)), the predicted frequency shifts of μPAW sensors in air and DI water were compared with experimental measurements (Fig. 10). Overall, the prediction results agree well with the measured values. As can be seen, the critical height of μPAW sensors becomes smaller (13 μm) when the sensors operate in DI water instead of air (15 μm). This is believed to be caused by the induced hydrodynamic loading and the additional mass on the micropillars and QCM surface. In addition, the frequency shift of sensors shows a sudden “drop and jump” near the micropillar’s critical height due to the coupling of the vibrations of quartz substrate and micropillars. The analytical model successfully captures nonlinear frequency responses with the change of micropillar heights.
Fig. 10
Comparison of Frequency shifts of μPAW operating in air and DI with model prediction
Figure 11 shows the model prediction for the frequency shift of μPAW devices in sucrose solutions with concentrations of 10 wt%, 30 wt%, and 50 wt%. As can be seen, the model can successfully capture the dynamics of μPAW operating in viscous solutions. The viscosity of the sucrose solutions can be easily calculated based on the frequency shift of μPAW with the developed model and the density of the solutions. The prediction results agree well with the experimental observations except for the micropillar with 13.9 μm height. This deviation is mainly due to the relatively low quality factor of the micropillar vibration near the critical height resulting in higher measurement errors.
Fig. 11
Comparison of frequency shifts of μPAW interacting with sucrose solution—measured values vs. prediction
Figure 12 presents sensitivity enhancements of μPAW devices (micropillar heights: 6.4 µm, 10.3 µm, 13.9 µm, and 18.1 µm) over traditional QCM-F. The results show that μPAW demonstrates a 20-fold improvement in viscosity measurement due to the resonant coupling between the micropillar and QCM substrate.
A new micropillar-enabled acoustic wave (μPAW) device was developed by fabricating a QCM PMMA micropillars on a QCM substrate to achieve ultrahigh sensitivity for viscosity measurement. Square cross-section micropillars were fabricated on QCM substrates with micropillar heights of 6.4 µm, 10.3 µm, 13.9 µm, and 18.1 µm and tested for measuring the viscosity of sucrose solutions. The results show that the μPAW is able to enhance the sensitivity of traditional QCM as much as 20-fold for viscosity measurement applications. Analyzing the LOD of μPAW and QCM-F reveals that the minimum detectable sucrose concentration using μPAW was 0.054 wt% compared to the traditional QCM, which was 0.54 wt%. The effect of flow conditions on the viscosity measurement of the μPAW device indicated that the frequency response of μPAW is independent of the flow conditions. At last, a theoretical model was developed to analyze the behavior of μPAW in viscous solutions. It is concluded that the viscosity effect on the μPAW devices can be analyzed by a modified two-degree-of-freedom model with additional effective masses. As the viscosity of the solution increases, the mass that is moving by the micropillar increases, leading to a frequency shift of the μPAW device.
Acknowledgements
The authors thank MicroChem Corp. (MA, USA) for providing PMMA material and financial support from National Science Foundation (NSF ECCS 2130716).
Declarations
Conflict of interest
The authors declare no conflicts of interests that are relevant to the content of this article.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Akyazi T, Basabe-Desmonts L, Benito-Lopez F (2018) Review on microfluidic paper-based analytical devices towards commercialisation. Anal Chim Acta 1001:1–17CrossRef
Arosio P, Hu K, Aprile FA, Müller T, Knowles TP (2016) Microfluidic diffusion viscometer for rapid analysis of complex solutions. Anal Chem 88:3488–3493CrossRef
Ash DC, Joyce MJ, Barnes C, Booth CJ, Jefferies AC (2003) Viscosity measurement of industrial oils using the droplet quartz crystal microbalance. Meas Sci Technol 14:1955CrossRef
Brizard M, Megharfi M, Mahe E, Verdier C (2005) Design of a high precision falling-ball viscometer. Rev Sci Instrum 76:025109CrossRef
Cullen P, Duffy A, O’Donnell C, O’callaghan D (2000) Process viscometry for the food industry. Trends Food Sci Technol 11:451–457CrossRef
Cullen P, O’donnell C, Houška M (2003) Rotational rheometry using complex geometries—a review. J Texture Stud 34:1–20CrossRef
Esfahani IC, Sun H (2023) A droplet-based micropillar-enhanced acoustic wave (μPAW) device for viscosity measurement. Sens Actuators A 350:114121CrossRef
Esmaeilzadeh H, Su J, Ji S, Cernigliaro G, Gehring FK, Sun H (2019) Lowest detectable protein immobilization measurement using an ultrasensitive micropillar-based quartz crystal microbalance (QCM-P) device. IEEE Sens J 19:9672–9679CrossRef
Esmaeilzadeh H, Zheng K, Barry C, Mead J, Charmchi M, Sun H (2021) Evaluating Superhydrophobic Surfaces under External Pressures using Quartz Crystal Microbalance. Langmuir 37:6650–6659CrossRef
Farsaeivahid N, Grenier C, Nazarian S, Wang ML (2022) A rapid label-free disposable electrochemical salivary point-of-care sensor for sars-cov-2 detection and quantification. Sensors 23:433CrossRef
Grattoni CA, Dawe RA, Seah CY, Gray JD (1993) Lower critical solution coexistence curve and physical properties (density, viscosity, surface tension, and interfacial tension) of 2, 6-lutidine+ water. J Chem Eng Data 38:516–519CrossRef
Gupta S (2014) Viscometry for liquids, calibration of viscometers, vol 322. Springer, ChamCrossRef
Inman BA, Etienne W, Rubin R, Owusu RA, Oliveira TR, Rodriques DB, Maccarini PF, Stauffer PR, Mashal A, Dewhirst MW (2013) The impact of temperature and urinary constituents on urine viscosity and its relevance to bladder hyperthermia treatment. Int J Hyperth 29:206–210CrossRef
Ji S, Ran R, Chiniforooshan Esfahani I, Wan K-T, Sun H (2021) A new microfluidic device integrated with quartz crystal microbalance to measure colloidal particle adhesion. In: ASME international mechanical engineering congress and exposition, American Society of Mechanical Engineers, 2021, pp. V005T005A075
Kanazawa KK, Gordon JG (1985) Frequency of a quartz microbalance in contact with liquid. Anal Chem 57:1770–1771CrossRef
Kang YJ, Yoon SY, Lee KH, Yang S (2010) A highly accurate and consistent microfluidic viscometer for continuous blood viscosity measurement. Artif Organs 34:944–949CrossRef
Li Y, Ward KR, Burns MA (2017) Viscosity measurements using microfluidic droplet length. Anal Chem 89:3996–4006CrossRef
Loock H-P, Wentzell PD (2012) Detection limits of chemical sensors: applications and misapplications. Sens Actuators B Chem 173:157–163CrossRef
O’sullivan C, Guilbault G (1999) Commercial quartz crystal microbalances–theory and applications. Biosens Bioelectron 14:663–670CrossRef
Puneeth S, Kulkarni MB, Goel SG (2021) Microfluidic viscometers for biochemical and biomedical applications: a review. Eng Res Express
Solomon DE, Abdel-Raziq A, Vanapalli SA (2016) A stress-controlled microfluidic shear viscometer based on smartphone imaging. Rheol Acta 55:727–738CrossRef
Srivastava N, Burns MA (2006) Analysis of non-Newtonian liquids using a microfluidic capillary viscometer. Anal Chem 78:1690–1696CrossRef
Su J, Esmaeilzadeh H, Zhang F, Yu Q, Cernigliaro G, Xu J, Sun H (2018) An ultrasensitive micropillar-based quartz crystal microbalance device for real-time measurement of protein immobilization and protein-protein interaction. Biosens Bioelectron 99:325–331CrossRef
Su J, Esmaeilzadeh H, Wang P, Ji S, Inalpolat M, Charmchi M, Sun H (2019) Effect of wetting states on frequency response of a micropillar-based quartz crystal microbalance. Sens Actuators, A 286:115–122CrossRef
Swindells JF, Snyder C, Hardy RC, Golden P (1958) Viscosities of sucrose solutions at various temperatures: tables of recalculated values, US Government Printing Office
Tabilo-Munizaga G, Barbosa-Cánovas GV (2005) Rheology for the food industry. J Food Eng 67:147–156CrossRef
Tadros TF (1992) Future developments in cosmetic formulations. Int J Cosmet Sci 14:93–111CrossRef
Vahid NF, Marvi MR, Naimi-Jamal MR, Naghib SM, Ghaffarinejad A (2019) X-Fe2O4-buckypaper-chitosan nanocomposites for nonenzymatic electrochemical glucose biosensing. Anal Bioanal Electrochem 11:930–942
Wang P, Su J, Dai W, Cernigliaro G, Sun H (2014a) Ultrasensitive quartz crystal microbalance enabled by micropillar structure. Appl Phys Lett 104:043504CrossRef
Wang P, Su J, Su C-F, Dai W, Cernigliaro G, Sun H (2014b) An ultrasensitive quartz crystal microbalance-micropillars based sensor for humidity detection. J Appl Phys. https://doi.org/10.1063/1.4880316CrossRef
Wang P, Su J, Su C-F, Dai W, Cernigliaro G, Sun H (2014c) An ultrasensitive quartz crystal microbalance-micropillars based sensor for humidity detection. J Appl Phys 115:224501CrossRef
Wang P, Su J, Gong L, Shen M, Ruths M, Sun H (2015) Numerical simulation and experimental study of resonance characteristics of QCM-P devices operating in liquid and their application in biological detection. Sens Actuators B Chem 220:1320–1327CrossRef
Yabuno H (2021) Review of applications of self-excited oscillations to highly sensitive vibrational sensors. ZAMM-Journal of Applied Mathematics and Mechanics/zeitschrift Für Angewandte Mathematik Und Mechanik 101:e201900009MathSciNetCrossRef
Yang M, Thompson M (1993) Multiple chemical information from the thickness shear mode acoustic wave sensor in the liquid phase. Anal Chem 65:1158–1168CrossRef
Die im Laufe eines Jahres in der „adhäsion“ veröffentlichten Marktübersichten helfen Anwendern verschiedenster Branchen, sich einen gezielten Überblick über Lieferantenangebote zu verschaffen.
