**3.2 Biomaterials actuators and micro-fabrication**

Designing microfluidic technologies for biochemical applications has proven to be a difficult task, and a properly working valve is a critical component in these technologies. Traditional micro-actuators are somewhat sophisticated components that needed additional electricity to operate. The use of sensitive smart polymer composites to govern flow eradicates this need for external power, output control, and complicated fabrication ploys, allowing them to be integrated within microfluidics streams and dwindle or perk up in response to an external stimulus, causing streams to open or close. Photo triggered polymerization inside the stream of a microfluidic chip that may be employed as a gate for changing; transmission, measuring, and closing of a PCR reaction vessel produced monolithic plugging PNiPAAm complexes using 5% methylenebisacrylamide. Because of their simple construction of sensors, the kinetic studies of the volume phase change process as a feature of gel structure and shape, the capacity of the sensors to thwart and supplant the transition between two fluids, anisotropic bulging of a polymer, as well as the ability to adapt to changing stimuli, responsive smart polymeric materials are the structural elements for microfluidic devices. Thermally sensitive smart polymeric materials have also been utilized to create "smart" affinities beads which can be transiently mounted on microfluidic walls of the channel just above MinCST in order to acquire the target biomaterials via its friendliness component. Proteomic functionalities, such as pre-concentration and isolation of soluble proteins on an embedded fluidics device, have been enabled by this technology. Many efforts were made to emulate live creatures' effective transition of chemical energy to mechanical energy. The bio-inspired actuators might be employed in future 'soft' technologies that are based on biological concepts rather than mechanical ones. Because bio-inspired actuators can tolerate extremely hostile conditions, they can also be utilized to pick up extremely small items in watery solutions. By contorting a barrier that subsequently occludes an opening, a system built on pH-sensitive smart polymeric discs of polymethacrylic acid-triethylene glycol dimethacrylate (PMAA-EG) has indeed been utilized to control medication delivery. The electronegative interpenetrating matrix (IPM) made of PVA with PNiPAAm was studied in aquatic NaCl solution for its moisture content and carrying behavior with electromagnetic current, with the goal of using it in bio-inspired sensors and devices that respond quickly to exterior electric fields. The immobilized smart polymer's prompted manipulation of interfacial characteristics at the solid-liquid interface has benefits in the development of microfluidics bio-analytical systems since they supply the actuation pressure necessary for both valving and dispensing functionalities in micro-dispensing gadgets [75–77].
