Biomimicry assignment

Name and description of organism:

[What is (are) the organism(s) identified as the inspiration for the work; write 1 short sentence describing the organism.]

Name Description
Polypterus senegalus This is fish belonging to the olden family Polypteridae, which was first discovered 96 million years ago. The fish is still retaining most of the family traits.
  1. Aspects suitable for biomimicry; description of usefulness of aspect to the organism; possible applications:

[What aspects of the organism are suitable for biomimicry (explain all aspects, not just the one in the papers)? How do these aspects serve the organism? What are the potential applications of these properties of the organism?]

Aspect Description Application
multilayered protective exoskeletal materials understanding the structure and design of different organisms with respect to sustaining of weights they

face in their encounters

Offers insightful knowledge for developing modified biological structural materials
multilayered simulations Understanding effective load-depth resistance, O–P modulus, energy

dissipation and micro-hardness

within the multilayer profile

Prediction of load-dependent effective modulus and

micro-hardness in homogeneous systems

underlying micromechanics of the multilayered


Four different nanostructural material layers namely: ganoine, dentine, isopedine and a bone basal plate


Effective ‘macroscopic’ indentation

Modulus which can be used to develop artificial tooth filler

  1. Methods:

[What methods were used to measure properties and/or create a mimic (and methods to characterize the mimic), etc.? e.g. , say AFM was used to … There is no need to report results here.]

  1. Characterization of organism/natural material (if attempted – but look also in references)
  2. Fabrication of replica (if attempted)
  3. Characterization of replica (if attempted)
Method Used to…
Immersion in buffered saline solution Preserve the samples removed during surgery
Instrumented nanoindentation Measure the penetration resilience, elastic and inelastic mechanical


Unpaired Student t-tests Evaluate the statistical difference between various datasets, using p < 0.05 as the minimum criterion
Two weeks tetracycline treatment with tablets Overcome chances of infection
Field emission

SEM and Optical microscopy

Nano imaging
Multiscale experimental and computational approach Elucidate design principles with regards to multi layering and grading


  1. Briefly describe stage of development (state of art/limitations, etc.):

[What were the results of the study? What has been learned since? If no mimic has been produced by anyone, say so – is there a reason it hasn’t been done? Is something commercially available? If not, is there a reason it is not commercially available? Be quantitative – if they make a mimic, how does it compare to the natural material? Did they accomplish what they set out to do? Will the mimic really work for the specified application? What are the stated limitations? What other limitations can you think of? This should be the longest section. You should show that you’ve read associated scientific literature and understand the concepts and think critically about them.]

Past Research

Most recent research on Polypterus senegalus were focused on: mineralized biological tissues design strategies [1], crystalline nucleation, structure and growth [2], bio macromolecular reinforcement, crystal texture modulation [3], amorphous phase stabilization, nano scale length effects as well as heterogeneity among others. However, more information was still lacking on mechanical characteristic of individual fish scales. This research focused on using a multiscale, procedural and mathematical approach to design such principles


Based on the research study carried out by [4], the following were the results:

  1. i) The Oliver–Pharr computed indentation modulus (EO–P) as well as the hardness (HO–P) reduced in value as distance increases from the outer towards the inner surfaces of the scale.
  2. ii) Material layers were significantly found to differ in mechanical characteristics.
  • iii) EO–P and HO–P approximately experienced negative linear gradation around the outer and within the underlying layers.
  1. iv) There was no detectable gradation in Isopedine and bone
  2. v) Interfaces at Ganoine–dentine and dentine–isopedine experienced steep gradation in comparison to their adjacent layers.

Mimic and associated limitation

Critical material layer sequence formed by reversing the dentine and ganoine layers in a virtual micro indentation may result in enlarged junction tensile normal and shear pressure, thus enhancing delamination [5].

Following observed that the dentine – ganoine interface in Polypterus senegalus scales with capability of arresting cracks just like in mammalian teeth, this structure can be modified to form human tooth fillers. However, this has not been done so far pending further research on compatibility of implant with the body system as well as other necessary investigation [4].

The general multilayered protective exoskeletal materials capable of yielding a mechanistic knowledge of how various organisms were developed and evolved to cope with the loads they encounter in their surroundings. This knowledge was key in the development of modified biologically inspired materials such as first responder and military vehicle armour applications [6].

Spatially non homogeneous stresses, a higher total junctional compression as well as delamination resistance can be made possible due to rough interlocking interface between the layers. The importance of such multiscale structural materials may be employed to the design of modified biomimetic structures [6].

  1. Nanoscale aspect:

The research summarized here in [4] dealt with nano scale size particles. The sizes of length given, say 500µm lies within nano scale dimensions.

  1. References:

[1] Kundrat, M.E., 2010. A Comprehensive Series for Predicting Bone Dynamics: Forecasting Osseous Tissue Formation Using the Molecular Structure of a Biomaterial (Doctoral dissertation, University of Dayton).

[2] Chen, P.Y., Schirer, J., Simpson, A., Nay, R., Lin, Y.S., Yang, W., Lopez, M.I., Li, J., Olevsky, E.A. and Meyers, M.A., 2012. Predation versus protection: fish teeth and scales evaluated by nanoindentation. Journal of Materials Research, 27(01), pp.100-112.

[3] Varshney, S.S.R., 2016. Biological and bio-inspired morphometry as a route to tunable and enhanced materials design (Doctoral dissertation, Massachusetts Institute of Technology).

[4] Bruet, B.J., Song, J., Boyce, M.C. and Ortiz, C., 2008. Materials design principles of ancient fish armour. Nature materials, 7(9), pp.748-756.

[5] Bruet, B.J.F., 2008. Multiscale structural and mechanical design of mineralized biocomposites (Doctoral dissertation, Massachusetts Institute of Technology).

[6] Ortiz, C. and Boyce, M.C., 2008. Bioinspired structural materials. Science, 319(5866), pp.1053-1054.


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