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Villapún, et al.
microstructure, production costs, and initial investment. of the part (Figure 2C). This is emphasized when the
Notably, the limited rating for post-processing desired application of the technologies in its current state
and mechanical properties may indicate that some (Figure 5C) or if their main shortcomings are overcome
stakeholders are not completely aware of their importance. (Figure 5D) is considered. The development of new
Alternative, this may also suggest that old, well-known products only increases in the medical field once the
AM limiters are either being subsided by the advances of current issues are addressed, while design only considers
the technology or accepted as an inevitable part of these the use of AM to modify existing products in the same
processes. Other barriers mentioned during the survey scenario. Consequently, although personalized medicine
include limited standardization, few materials available, is the main initiator of AM uptake, enhancement of the
software reliability, complex machine certification or the technological state of AM may lead to new opportunities.
manual labor involved in de-powdering (specific to metal Materials and mechanical properties were shown to
AM processes), and post-processing. be critical for the success of the device and may constrain
Current and future perspectives were analyzed the use of 3D printing (Figure 2B and C); however,
by surveying the likelihood of further incorporating these are not perceived as a huge disadvantage, with only
or increasing the presence of AM given the state of the microstructure mentioned as a constraint (Figure 5B).
technologies as of now (Figure 5C and Table S17) or Feedstock for most systems is highly specialized, which
in a hypothetical future (Figure 5D and Table S18) requires specific manufacturing processes and control. As
where the previously mentioned limitations were eased. the technology is still emerging, the limited demand for
While similar core interests are shared in both scenarios, bulk feedstock and poor guidance on quality management
differences can be observed between respondent groups. and traceability has reduced the number of suppliers and
The state of existing processes seems to be a tool to design materials, resulting in material availability being critical
new products and develop new techniques, although to AM expansion [2,9,40] . Based on this survey, it seems
the latter varies with expertise. In the case of design likely that the respondents are mainly concerned about
respondents, the design of new products, 50%, should be material processing rather than raw feedstock availability.
the main area of focus for this technology; however, the Partly, this may have been caused by the specificity of the
pursuit of product modification, designing new products medical field where there has been a preference for the use
and development of new techniques through AM is of a reduced number of base materials considered as gold
shared between manufacturing (33.3%, 33.3%, and standards (i.e., Titanium alloys or PEEK) . In contrast
[45]
22.2%, respectively) and medical (23.5%, 17.6%, and to material availability and given the intrinsic connection
52.9%, respectively). Specific areas where 3D printing between microstructure and mechanical properties is thus,
could be effectively used included: Introduction of novel surprising to see the disconnection showed between these
structures, research, and any field where customization is two parameters in the current survey. Nevertheless, much
required or desired. work has been done by the research community on the link
The general trend undergoes a slight shift in the between system inputs and final part properties for powder
hypothetical case that current limitations are subsided bed fusion [39,46,47] and material extrusion [48,49] , two of the
with the design of new products being the main focus area, most used systems by the respondents. Regardless of the
followed by a similar interest in product modification and advances indicated by the academic community, it seems
technique development. Small variations in interest take likely that concerns about anisotropy, delamination, or
place in academia, manufacturing and medical experts; variations in mechanical behavior from well-established
however, a more radical shift occurs in design. For once, traditional techniques [29,50] are still affecting the uptake of
these professionals did not consider the use of AM to these technologies.
modify products in the current state of the technology; Numerous reviews on AM state waste reduction
nevertheless, 28.6% agree that this should be the main and sustainability as main advantages over conventional
avenue alongside the design of new products and processes, generally, as a result of reduced waste material,
prototyping. Nevertheless, the Fisher exact test did not less energy intensive and polluting manufacturing
reveal a significant link between expertise or these fields. processes, efficient designs and decentralization of
Based on this survey, the main potential the supply chain, which could result in significant cost
observed in medicine seems to be consistently focused savings [3,4,38,51-53] . While interest in using sustainability as a
on personalization and control of the final design marker for system selection has been shown (Figure 2A),
(Figure 4A and 5A). Similarly, lead time reduction waste reduction was not considered an advantage
is clearly perceived as a benefit for the uptake of AM. (Figure 5A), with cost selected as the most consistent
Thus, it is likely that all experts agree with the general AM concern throughout the questionnaire. In this regard,
trends reported in literature; nevertheless, it appears it must be said that current AM technologies are still
that personalization is not likely critical to the success classed as emerging and perhaps lack the infrastructure

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