Abstract:
the practice of learning from and emulating nature - which can be increasingly realized in engineering applications
due to progress in additive manufacturing (AM). AM has grown tremendously in recent years, with
improvements in technology and resulting material properties sometimes exceeding those of equivalent parts
produced by traditional production processes. This has led to the industrial use of AM parts even in highly
critical applications, most notably in aerospace, automotive and medical applications. The ability to create parts
with complex geometries is one of the most important advantages of this technology, allowing the production of
complex functional objects from various materials including plastics and metals that cannot be easily produced
by any other means. Utilizing the full complexity allowed by AM is the key to unlocking the huge potential of this
technology for real world applications – and biomimicry might be pivotal in this regard. Biomimicry may take
different forms in AM, including customization of parts for individuals (e.g. medical prosthesis, implants or
custom sports equipment), or optimization for specific properties such as stiffness and light-weighting (e.g.
lightweight parts in aerospace or automotive applications). The optimization process often uses an iterative
simulation-driven process analogous to biological evolution – with an improvement in every iteration. Other
forms of biomimicry in AM include the incorporation of real biological inputs into designs (i.e. emulating nature
for its unique properties); the use of cellular or lattice structures – for various applications and customized to the
application; incorporating multi-functionality into designs; the consolidation of numerous parts into one and the
reduction of waste, amongst others. Numerous biomimetic design approaches may be used – broadly categorized
into customized/freeform, simulation-driven and lattice designs. All these approaches may be used in combination
with one another, and in all cases with or without direct input from nature. The aim of this review is to
unravel the different forms of biomimetic engineering that are now possible – focusing mainly on functional
mechanical engineering for end-use parts, i.e. not for prototyping. The current limits of each design approach are
discussed and the most exciting future opportunities for biomimetic AM applications are highlighted.
