Table 2.

Other broad areas of 4D Printing.

S. No	Areas	Description
1	Fashion	•Smart clothing, shoes, and other items may change colour in response to environmental stimuli. Depending on the situation, they may modify their functioning to keep the body cool or heated
		•Shoes, clothes, jewellery, and other items that can be altered in size to better fit various people
		•Self-assembly and disassembly shoes can be utilised to save manufacturing labour and to lessen the effort required to wear the shoes
		•Self-repairing fabric can be used to 4D print the clothes
2	Medical	•Bioprinting is a type of 4D printing that can be used to create artificial tissues, bio-organs, and other medical devices that might save millions of lives
		•The bio-printed smart material, which changes shape and size once it reaches the target area via some external medium, may be employed in a variety of ways, including opening clogged arteries and veins
		•Smart printed medications may also be utilised to deliver individual drugs to specific human organs/parts/locations
3	Aerospace	•Thus, to reduce the risks of failure, self-repairing materials can be employed in the spacecraft's construction
		•It is also feasible to have a self-adjusting body to regulate the aircraft's aerodynamics
		•Spacesuits can be made from flexible metal textiles
4	Automotive	•Colour-changing automobiles, smart tyres that change form while parking to make the vehicle theft-resistant, and smart interiors that can change colour, size, and usefulness are all possibilities
		•Self-deploying inlet valves, vents etc. to control engine temperature, adaptive vehicle seats (can reshape their configuration) to increase comfort and functionality
5	Electronics	•4D printed smart/adaptive sensors (soft tactile sensors), electronic gadgets (which can fold down to a tiny size when not in use), micro components, and other devices can alter the shape, size, and functionality as needed
6	Constriction	•4D printed pipes that can expand and contract to control fluid flow. In addition, self-repairable pipes can handle a variety of plumbing issues
		•Moveable 4D printed bricks to decrease stress and maximise space use
		•4D printed self-assembly furniture changes shape in response to light, water, etc.
7	Defence	•4D printed armour, smart camouflaged clothing, etc. are only a few of the conceivable applications of this technology in the defence industry
		•4D printed weapons that can alter shape and functioning depending on the scenario on the battlefield
8	Education	•4D printing may be used in the education sector to teach and lead students, allowing them to learn new things, discover new possibilities, and conduct experiments on printed items