Table 4.

Technological, economic, environmental and social aspects of 3D printing.

Aspects of 3DP	Description	Source
Technological	Research, documentation, preservation, cultural heritage, and educational purposes	[78]
	Home fabrication and business model innovation	[79]
	3D printed electronics	[80]
	Fabrication of functional heat exchangers and turbine blades	[81,82]
	Energy harvesting (ocean, wind, human body, vibrations etc.)	[78]
	Energy-efficient Internet-of-Things (IoT) wireless sensors	[83]
	Additive printing of jewellery and fashion products	[84]
	Surgical planning, prosthetics, organ printing, implants, tissue engineering and scaffolds	[85,86]
	Repair of complex aerospace components such as engine blades/vanes and combustion chamber	[87]
	3D printed nasopharyngeal swabs for diagnosis and emergency respiration device	[88]
Economic	3DP is expected to be a 230–550 billion US $ market by 2025, with significant economic impacts for high-value, low volume and customized products	[89]
	3DP is considered to influence five significant markets by 2025, including consumer goods, aerospace, automotive, medical equipment and tooling	[10,90]
	3DP enables complex geometries and lightweight designs, leading to reduced product life cycle costs and fuel savings in aviation	[91]
	High automation of 3DP changes labour patterns, labour workforce is needed only in pre-processing and postprocessing (suitable for developed countries)	[92,93]
	An expected decline in exports and imports	[94]
	Shorter supply chains, reduced need for tooling & centralized manufacturing, digital designs replace physical goods in supply chains	[9,95]
	Reduced time from manufacturing to market and consumption of transportation	[10,96]
Environmental	Significantly reduced manufacturing-, material-related and life cycle energy demands of products and their CO2 emissions due to shortened and more direct manufacturing	[97]
	Reduced energy demands and CO2 emissions of airplanes and cars due to 3DP based lightweight designs, cost-effective manufacturing of complex geometries	[90,98]
	In aerospace manufacturing, 3DP tends towards a buy-to-fly ratio of almost 1:1, leading to a significant reduction in resource demands and waste amounts	[99]
	3DP needs no lubricants, coolants, or other environmentally harmful substances	[10]
	3DP can re-use up to 95–98 % of the unfused raw material and up to 40 % saving of material-wastage	[100]
	Energy demands and CO2 emissions due to industrial manufacturing are expected to reduce by maximally 5% through 3DP by 2025	[10]
Social	Enhanced availability of localized means of production in consumer countries	[9]
	Information technology education is required as a consequence of a rapid shift of companies towards 3DP based digital designs/ideas	[101,102]
	Socio-economic development in rural areas due to the easy accessibility of the objects	[10]
	Spare parts or lab equipment can be fabricated on-demand anywhere owing to an open-source 3DP	[103]
	Need strict control of 3DP technologies due to the availability of open-source firearms and blueprints of weapon designs	[104]
	Compatible for emergencies like COVID-19 pandemic due to design mobilization and reduced need for the human workforce	[88]