Figure 2 - uploaded by Karol Malecha
Content may be subject to copyright.
Source publication
A novel bonding method of glass-covered low-temperature co-fired ceramics (LTCC) to transparent polydimethylsiloxane (PDMS) polymer is reported in this paper. The irreversible bonding between both materials was achieved by exposing their surfaces to an oxygen plasma. The influence of different plasma treatment process parameters (system power, time...
Context in source publication
Citations
... Coating materials such as Al 2 O 3 , TiO 3 -AlO 3 , Cr 2 O 3 , and Y 2 O 3 -ZrO 2 are used to strengthen the interfacial bond. For instance, [23] developed a novel reversible protocol for LTCC-PDMS bonding . The report showed that the adhesion of PDMS-LTCC pair changed depending on the plasma exposure. ...
Native ceramics are known for their characteristics of rigidity for which it has attained remarkable use across a wide spectrum of industrial applications, especially in microelectronics. However, with redefining protocol in manufacturing and a shift in fabrication and material procession technology, innovations in ceramic technology have drifted markedly to the adoption of the term “flexible ceramics.” In ceramics, being flexible implied the ability to bend, fold and shape processed ceramics to suit production requirements. In addition to the present capability to produce foldable, stretchable thin-film ceramics from natively rigid ceramic base materials, flexible ceramics could also be impacted with desired properties to match required biocompatibility requirements in the biological environment. Thus a flexible and biocompatible ceramic-based material could become a candidate material for application for microfluidic devices in biomedical domains. Hence, one could ascertain that flexible ceramics materials used in microfluidic industries are tailored by certain microfabrication protocols to meet desired conditions in microenvironments for which the miniaturized device is intended to achieve. Thereafter, the flexibility impacted onto ceramics by way of fabrication and post-fabrication treatments can bestow a versatile functionality on native ceramic with the previously monotonic application. In addition, the possibility to enact integrated low-voltage control architecture onto a flexible microfluidics platform further increases the acceptability and versatility of thin-sheet ceramic-based microdevices.
... The polydimethylsiloxane (PDMS) is selected as a covering material due to its biocompatible, non-toxic, non-flammable and transparent properties. The PDMS sheet of required dimension can be bonded with LTCC [43,44]. The reaction chamber is designed in circular shape in order to smooth the movement of the liquid and to avoid residual in the chamber. ...
In present paper, thermal simulation of LTCC based micro-chamber has been performed which is a key part of RT-PCR device. The RT-PCR device plays an important role in SARS-CoV-2 testing. The rRT-PCR system requires three different thermal cycles for DNA amplification which takes part in detection of SARS-CoV-2. The thermal cycle can be equipped using a heater structure in the chamber. A new LTCC based technique to develop micro-chamber has been designed and simulation has been performed using COMSOL to optimize thermal properties. Temperature distribution for a micro-chamber at three different voltages has been simulated. The temperature distribution is more uniform in micro-chamber with a buried metallic layer in comparision to micro-chamber without a metallic layer. The heater and temperature sensor were located outside the reaction chamber. A platinum based pattern as PTC temperature sensor is used in temperature measurement.
... Although photolithography is widely used to fabricate masters or molds for making PDMS-based microfluidic devices with high precision, it is a lengthy procedure with many steps (Fig. S4) [13,[57][58][59]. This is even worse when fabricating devices with non-planar microfluidic channels (i.e., channels of varying depths), which requires multiple rounds of photoresist layering and alignment [15,49,[59][60][61][62][63][64][65]. In contrast, the technique of 3D printing has rapidly developed over the past a few years into an affordable technology that has been utilized in teaching, manufacturing, medical device development, and personalized healthcare for easy fabrication of 3D objects [66][67][68][69][70][71][72][73][74][75][76][77][78][79]. ...
The conventional approach for fabricating polydimethylsiloxane (PDMS) microfluidic devices is a lengthy and inconvenient procedure and may require a clean-room microfabrication facility often not readily available. Furthermore, living cells can't survive the oxygen-plasma and high-temperature-baking treatments required for covalent bonding to assemble multiple PDMS parts into a leak-free device, and it is difficult to disassemble the devices because of the irreversible covalent bonding. As a result, seeding/loading cells into and retrieving cells from the devices are challenging. Here, we discovered that decreasing the curing agent for crosslinking the PDMS prepolymer increases the noncovalent binding energy of the resultant PDMS surfaces without plasma or any other treatment. This enables convenient fabrication of leak-free microfluidic devices by noncovalent binding for various biomedical applications that require high pressure/flow rates and/or long-term cell culture, by simply hand-pressing the PDMS parts without plasma or any other treatment to bind/assemble. With this method, multiple types of cells can be conveniently loaded into specific areas of the PDMS parts before assembly and due to the reversible nature of the noncovalent bonding, the assembled device can be easily disassembled by hand peeling for retrieving cells. Combining with 3D printers that are widely available for making masters to eliminate the need of photolithography, this facile yet rigorous fabrication approach is much faster and more convenient for making PDMS microfluidic devices than the conventional oxygen plasma-baking-based irreversible covalent bonding method.
... Bonding of the LTCC with PDMS (polydimethylsiloxane) -reliable bonding thanks to the oxygen plasma surface activation of the LTCC and the PDMS surfaces [9]. The method is widely used technique for microsystems with optical detection. ...
... During the modification process ions hit the surface of materials which eliminates the particles formed in the post-production process and micropollutants from the room. Besides they can also lead to changes in the chemical structure of the modified surface, which in many cases is justified [9]. ...
... The selected properties of the materials that act as substrates for microfluidic or/and microwave components in the microfluidic-microwave devices. Based on [19][20][21][22][23][24][25][26][27][28][29][30][31]. ...
The constant increase in the number of microfluidic-microwave devices can be explained by various advantages, such as relatively easy integration of various microwave circuits in the device, which contains microfluidic components. To achieve the aforementioned solutions, four trends of manufacturing appear—manufacturing based on epoxy-glass laminates, polymer materials (mostly common in use are polydimethylsiloxane (PDMS) and polymethyl 2-methylpropenoate (PMMA)), glass/silicon substrates, and Low-Temperature Cofired Ceramics (LTCCs). Additionally, the domains of applications the microwave-microfluidic devices can be divided into three main fields—dielectric heating, microwave-based detection in microfluidic devices, and the reactors for microwave-enhanced chemistry. Such an approach allows heating or delivering the microwave power to the liquid in the microchannels, as well as the detection of its dielectric parameters. This article consists of a literature review of exemplary solutions that are based on the above-mentioned technologies with the possibilities, comparison, and exemplary applications based on each aforementioned technology.
... Moreover, in many cases, the chemical analysis is based on observations of the phenomenon occurring within the microsystem (mixing, fluorescence, color changing, transport of particles suspended in flowing medium), and non-transparent LTCC materials preclude this type of study. To solve this problem, our group developed a method of LTCC with transparent PDMS bonding using DBD (dielectric barrier discharge) argon or argon/oxygen plasma [10]. The transparent cover allows for analysis of fluid flow and mixing inside the channels and chambers, which is an invaluable tool in microsystem diagnostics. ...
... The method of bonding LTCC and PDMS was previously described [10,11]. In this process, the surface is modified through plasma treatment. ...
... After such modification, PDMS can be bonded to LTCC, using oxygen [10] or argon [11] plasma. Before the process, a glaze layer is screen-printed in order to reduce surface roughness and to introduce oxygen functional groups. ...
One of the major issues in microfluidic biosensors is biolayer deposition. Typical manufacturing processes, such as firing of ceramics and anodic bonding of silicon and glass, involve exposure to high temperatures, which any biomaterial is very vulnerable to. Therefore, current methods are based on deposition from liquid, for example, chemical bath deposition (CBD) and electrodeposition (ED). However, such approaches are not suitable for many biomaterials. This problem was partially resolved by introduction of ceramic–polymer bonding using plasma treatment. This method introduces an approximately 15-min-long window for biomodification between plasma activation and sealing the system with a polymer cap. Unfortunately, some biochemical processes are rather slow, and this time is not sufficient for the proper attachment of a biomaterial to the surface. Therefore, a novel method, based on plasma activation after biomodification, is introduced. Crucially, the discharge occurs selectively; otherwise, it would etch the biomaterial. Difficulties in manufacturing ceramic biosensors could be overcome by selective surface modification using plasma treatment and bonding to polymer. The area of plasma modification was investigated through contact-angle measurements and Fourier-transform infrared (FTIR) analyses. A sample structure was manufactured in order to prove the concept. The results show that the method is viable.
... As a result, one may modify surface tension, chemical activity or mechanical properties. Local modifications using micro-plasma are applied to fabrication of microfluidic modules [17]. Because micro-plasma can be focused on a much smaller surface than the conventional one, it is possible to modify surface with a resolution of 200 µm [18]. ...
... An important advantage of the LTCC process is the possibility to separately test every layer of multilayered structure [15]. LTCC-based microfluidic chips have chemical and temperature stability, very good mechanical properties and the possibility to be combined with structures and components from other technologies [16]. For some applications, drawback of LTCC technology is non-transparency, thus it is necessary to perform bonding of LTCC structure with other transparent materials, such as PDMS [17,18] or glass [19]. ...
Microfluidics, one of the most attractive and fastest developed areas of modern science and technology, has found a number of applications in medicine, biology and chemistry. To address advanced designing challenges of the microfluidic devices, the research is mainly focused on development of efficient, low-cost and rapid fabrication technology with the wide range of applications. For the first time, this paper presents fabrication of microfluidic chips using hybrid fabrication technology—a grouping of the PVC (polyvinyl chloride) foils and the LTCC (Low Temperature Co-fired Ceramics) Ceram Tape using a combination of a cost-effective xurography technique and a laser micromachining process. Optical and dielectric properties were determined for the fabricated microfluidic chips. A mechanical characterization of the Ceram Tape, as a middle layer in its non-baked condition, has been performed and Young’s modulus and hardness were determined. The obtained results confirm a good potential of the proposed technology for rapid fabrication of low-cost microfluidic chips with high reliability and reproducibility. The conducted microfluidic tests demonstrated that presented microfluidic chips can resist 3000 times higher flow rates than the chips manufactured using standard xurography technique.
... epoxies) [16] and could often be cured at elevated temperatures or by UV light. Recently, (3-Aminopropyl)triethoxysilane (APTES) [17], (3-Mercaptopropyl)trimethoxysilane (MPS) [18] and low-temper ature co-fired ceramics (LTCC) [19] have also demonstrated effectivebonding to PDMS with plastic materials. ...
In this paper, we present an improved method to bond poly(dimethylsiloxane) (PDMS) with polyimide (PI) to develop flexible substrate microfluidic devices. The PI film was separately fabricated on a silicon wafer by spin coating followed by thermal treatment to avoid surface unevenness of the flexible substrate. In this way, we could also integrate flexible substrate into standard micro-electromechanical systems (MEMS) fabrication. Meanwhile, the adhesive epoxy was selectively transferred to the PDMS microfluidic device by a stamp-and-stick method to avoid epoxy clogging the microfluidic channels. To spread out the epoxy evenly on the transferring substrate, we used superhydrophilic vanadium oxide film coated glass as the transferring substrate. After the bonding process, the flexible substrate could easily be peeled off from the rigid substrate. Contact angle measurement was used to characterize the hydrophicity of the vanadium oxide film. X-ray photoelectron spectroscopy analysis was conducted to study the surface of the epoxy. We further evaluated the bonding quality by peeling tests, which showed a maximum bonding strength of 100 kPa. By injecting with black ink, the plastic microfluidic device was confirmed to be well bonded with no leakage for a day under 1 atm. This proposed versatile method could bond the microfluidic device and plastic substrate together and be applied in the fabrication of some biosensors and lab-on-a-chip systems.
... The PCM membrane was first saturated with water. Argon, oxygen, or argon/oxygen plasma have been used to bond the PDMS and glass-covered LTCC together [25][26][27]. In this work, The PDMS-LTCC substrate and PDMS-glass substrate were manually aligned and mechanically secured with spring clips instead of irreversible bonding using the plasma method. ...
In this paper, a microfluidic platform for real-time monitoring of dissolved oxygen in a flowing microfluidic environment fabricated using low temperature co-fired ceramic (LTCC) technology is described. The fabricated Clark-type oxygen sensor consisted of three electrodes (working electrode, counter electrode and Ag/AgCl reference electrode), a solid-state proton conductive matrix (Nafion 117 membrane) and polydimethylosiloxane (PDMS) as the oxygen permeable membrane (OPM). The use of a solid-state proton conductive matrix as the electrolyte in the design of the oxygen sensor makes it feasible integrate this device in a typical LTCC fabrication process. Cyclic voltammetry and chronoamperometry measurement were used to characterize electrochemical properties of the developed oxygen sensor. The reduction current was linearly related with the dissolved oxygen concentration ranging from 0 to 8.1 mg/l under different flow conditions (0.0–1.0 ml/min). The residual currents of the oxygen sensor were less than 3.5% of that measured in oxygen saturated state, and the average response time was 10.9 s. The current device represents an improved Clark-type oxygen sensor with the advantages of easy fabrication, flexible configuration, fast response time, incorporation of microfluidic analyte introduction and real-time detection of dissolved oxygen. The potential applications include material synthesis, cell culture, biological assays incorporating controlled introduction of reagents or analytes and real-time monitoring of dissolved oxygen in a microfluidic environment.
