Variations for Oyster Shell | Alginate Composite 3D print


Oyster Shell | Alginate Composite 3D print

Created By: Markos Georgiou  
Image Credit :
Calcium carbonate composites, 3D Printed, Food Waste

Research Biomimetic Regulation of Microbially Induced Calcium Carbonate Precipitation Involving Immobilization of Sporasarcina pasteurii by Sodium Alginate


Step one

  • Wash and clean oyster shells from any remains 
  • Boil the shells for 30 minutes 
  • In the oven, bake the shells for 45 minutes at 180°C to make them more fragile 
  • Using a cloth on top, smash the shells into smaller pieces with a hammer
  • Place the pieces in the oven for another 45 minutes at 200°C. It will make them more brittle and easier to grind
  • In a blender, grind the shells into the finest powder possible
  • Sieve the ground shells to obtain a particle size of 40 micron

Step two

  • To create the alginate solution (binder), add Sodium Alginate powder ( 2.5% of total weight) and Water ( 97.5% of total weight)
  • Stir well until a gel is formed and let sit for at least 3 hours

Step three

  • Measure the desired amount of oyster shell powder 
  • Add binder to the powder until the right ratio is met. The powder : binder ratio is 1 : 0,4

Step four

  • Measure the total weight of the mixture and add 5% honey. Stir well until all dry powder is wet and homogenous. 
  • Insert the paste into the extruder container carefully avoiding air gaps. For this project, the material was printed with a biogun but any 3D printer can be used.

Step five

This recipe uses waste oyster shells collected from local restaurants and bars, giving them the opportunity to be turned into useful and valuable ceramic-like materials and products. Design Opportunity Oysters are a great source of Calcium Carbonate (CaCO3) with a content up to 95%, whose mining accounts for 8% of global emissions and seen as a valuable material while on the contrary, massive amounts of shells are produced as a by-product in the fish industry and discarded as a nuisance waste. Their collection, transportation, and disposal are harmful to the environment and cost money.

To find out more about how Markos used his biomaterial and design the hand-held Biogun 3D printer, follow these links below: