**3.6 Thermoplastic-polymers Lab-on-a-Chip**

Irrespective of the opportunity that it is a little bit more uncertain and expensive to actualize than PDMS, thermoplastics are great contender for the manufacture of LoCs. Thermoplastic polymers are generally utilized by specialists to manufacture LoCs. Polymethyl methacrylate (PMMA), given its transparency, can be used as the positive tone photoresist in X-ray lithography and e-beam lithography processes [38]. Cyclic-olefin Copolymer (CoC) polymer is a popular fabrication material for various applications, including lenses and medical devices. CoC can also be used for the 3D printing of microfluidic LoC devices. PolyCarbonate (PC), which is more inert to chemical solvent than PDMS therefore, can be useful for some LoC applications where PDMS are not suitable for the required LoC applications. However, fabricating LoCs using PC requires investment intensive high-pressure embossing micromachining tools. Poly vinyl alcohol (PVA) is used for fabricating sophisticated LoCs with three-dimensional polymer microstructures. PVA can be dissolved in water but not in solvents, so they can be used as sacrificial materials. One more type of polymer not directly used for fabricating LoCs but still useful for biomedical application is Parylene. Parylene allows the transmission of waves in the visible spectrum, and it is not porous and can be coated onto electronics to prevent it from

#### *Contemporary Developments and Perspectives in International Health Security - Volume 1*


#### **Table 4.**

*Physical properties of PDMS [36].*


#### **Table 5.**

*Comparison between polymer and glass as the substrate of microfluidic LoC systems for biomedical and chemical applications [36].*

**203**

cultures [45].

*mHealth-Based Microfluidic Lab-on-a-Chip for International Health Security*

**4. Advantages of microfluidic Lab-on-a-Chip technology**

Globally, every country confronts parallel challenges in keeping its inhabitants healthy and preventing the cross-border spread of infectious diseases. Biomedical engineers, synthetic chemists, and biologists along with public health professionals are evaluating the potentiality of microfluidic LoC technology in the context of international public health security. In recent years, certain applications have emerged, from the detection of infectious diseases to diagnostics for international public health [41]. Several on-chip clinical assessments have also appeared include cell analysis, cytometry, blood analysis, nucleic acids amplification, genetic mapping, enzymatic assays, peptide analysis, protein separation, toxicity analysis, and bioassays [42]. In the area of drug research, the LoC devices have gradually became significant with the prominence on cell targeting, clinical trials, drug synthesis, pharmaceutical formulations, and product management process [43]. The LoC devices are found promising in the analysis of drugs and determination of optimal dosages. This is especially useful for testing the synergistic effect of combined drugs [44]. In recent past, microfluidic LoCs presented an exclusive prospect to replicate natural veins for testing nanoparticles as drug carriers for targeting cells or, moreover, presented opportunities for investigate in vitro metabolism of biological

Compactness, portability, modularity, embedded computing, automated sample handling, low electronic noise, limited power consumption, and straightforward integration of various components are some notable technical advantages of LoC devices [46]. Furthermore, LoC devices are capable of supporting a wide range of processes such as sampling, routing, transport, dispensing, and mixing, mostly with reduced moving or spinning mechanisms [47]. Due to their small size, the LoC devices offer precise fluidic transportation via the use of electrokinetics or micropumping, efficient separation of the liquid samples, and precision in the measurement of samples [48]. Likewise, the LoC devices can reduce the time of synthesis of a product and the time of analysis of a sample because of the small fluidic volumes

corroding and avoiding electrical short circuiting [34]. For specific applications, some exploration groups acquired great outcomes with thermoplastic-polymers LoCs, and since it is feasible to integrate microelectrodes into these polymers, thermoplastic polymers are having evident opportunity for the industrial develop-

The earliest LoCs were fabricated in silicon, and it appears like a significant characteristic decision since smaller scale innovations depend on the micromachining of silicon [35]. These days' scientists do not frequently utilize silicon for LoC, for the most part since silicon is costly, not optically nontransparent, and requires a spotless room. Moreover, the electrical conductivity of silicon makes it difficult to use for LoC operations. Still, silicon is relevant choice for the industrialization of some LoC applications. Analogous to silicon, glass is also the earliest fabrication material for LoCs. Glass is a hard material to fabricate chip but a useful material due to its inertness and transmutability of wavelengths in UV, IR, and visible regions [40]. However, fabricating LoCs in glass requires hazardous chemicals and lengthy time intervals, expensive facilities. From an exploration perspective, the creation of glass LoCs requires clean rooms and specialists with solid information of microfab-

*DOI: http://dx.doi.org/10.5772/intechopen.90283*

**3.7 Silicon and glass Lab-on-a-Chip**

ment of some LoCs [39].

rication techniques.

#### *mHealth-Based Microfluidic Lab-on-a-Chip for International Health Security DOI: http://dx.doi.org/10.5772/intechopen.90283*

corroding and avoiding electrical short circuiting [34]. For specific applications, some exploration groups acquired great outcomes with thermoplastic-polymers LoCs, and since it is feasible to integrate microelectrodes into these polymers, thermoplastic polymers are having evident opportunity for the industrial development of some LoCs [39].
