technology due to the integration of several steps into single auto-

mated platforms [15], making them powerful platforms for single

cell studies. Cultivation, separation/isolation, detection and analy-

sis of single cells can be conducted properly within microfluidic

devices at high throughput rates, high reproducibility and high

automation, with easy and low-cost operation [68]. There is an

increasing demand for these microfluidic technologies in the global

market. According to Market and Market reports, the microfluidic

market share was $15.7 billion in 2020, and this share is expected

to reach $44 billion in 2025. This market has been segmented into

hospitals and diagnostic centers, academic and research institutes,

and pharmaceutical and biotechnology companies. The hospitals

and diagnostic centers are the areas with the highest market share in

this field. The microfluidic technologies continue to grow and

develop with university and industry collaborations [9].

The choice of material for microfluidic devices is important in

studying cells. In recent years, alternative materials to glass and

silicon have been researched among elastomeric and thermoplastic

materials.

Thermoplastic

materials

composed

of

linear

and

branched molecules are highly preferred due their easy surface

modification and durability against temperature as well as pressure

changes, and they also do not suffer from any structural break-

down. However, it is not easy to satisfy the material requirements of

the specific biological applications. Optical properties, thermosta-

bility, chemical stability, and gas permeability are the key arguments

of the microfluidic device fabrications [2, 10]. Thermoplastic chips

must be biocompatible for cells to survive and transparent to moni-

tor them. For these reasons, polycarbonate, cyclo olefin polymer,

poly(methyl methacrylate) and polystyrene stand out compared to

other polymers. These polymers are commonly used in industrial

manufacturing and possess excellent optical qualifications. They

allow rapid prototyping [11, 12].

Fabrication methods of the thermoplastic devices are relatively

simple. Fabrication tools are low-cost and easy to use. Wet etching,

conventional machining, photolithography, hot embossing, injec-

tion molding, laser ablation and 3D printing are some examples of

production methods. Selection of fabrication method depends on

various factors, such as availability of technology and equipment,

cost, speed, and capability [13, 14]. In this chapter, the manufac-

ture of thermoplastic microfluidic devices with and without

integrated electrodes is explained for simple systems requiring no

active components such as micropumps, micro-valves, and sensors.

Photolithography, etching, deposition, hot embossing and thermo-

compression bonding methods are used for the desired device

fabrication and every step is explained in detail.

28

Elif Gencturk et al.