Biofabrication and additive manufacturing

9th of November - Fiorenzo Omenetto (Tufts)

Class slides recordings

In the biofabrication and additive manufacturing module we will discuss how we can use naturally derived materials for making and building. The guiding principle is to reinvent structural biopolymers into high-technological materials through basic principles of materials science, advanced fabrication and ingenuity. The class will be focused on silk and keratin, materials with thousands of years of history and that now can be engineered to serve at the interface between the biotic and abiotic world. The natural origin of biopolymers also allows for the engineering of materials with remarkably low-energy processing and little environmental impact. By discussing biopolymer regeneration, self-assembly and advanced fabrication we will not only explore a material platform technology at the interface between innovation and sustainability but also introduce a biomaterials based approach that can operate between growing anything and making anything.

Background reading

- Materials fabrication from Bombyx mori silk fibroin (

- New opportunities for an ancient material (

- A new route for silk (

- Silk Materials – A Road to Sustainable High Technology (

- Silk, the ancient material of the future - TED (

Lab homework assignments

1. Regeneration of silk fibroin into an aqueous suspension (please, refer to Step 1-23 in Rockwood et al. Nature Protocols, 6, 1612–1631 (2011) in background reading).

2. Fabrication of an edible, implantable, biodegradable diffraction grating through soft lithography (please, refer to Step 25H in Rockwood et al. Nature Protocols, 6, 1612–1631 (2011) in background reading).

3. Superfab Assignment - Biomanufacturing in 3D Using the silk suspension obtained in Assignment #1 in combination with a XYZ dispensing system for the 3D printing of silk fibroin


Aside from standard laboratory equipment such us personal protection garments, hot plates, spatula, etc. the following materials are required:

Extraction of silk fibroin

- Delipided and pre-washed silk cocoons (prepackaged, shipped to you by Silklab)

- Sodium carbonate (Sigma-Aldrich, cat. no. 451614,

- Ultrapure water

- Lithium bromide (LiBr, Sigma-Aldrich, cat. no. 213225,

- Slide-A-Lyzer dialysis cassette 3500 MWCO, 3–12 ml capacity (Thermo Scientific, cat. no. 66110,

- Syringe (20 ml; BD Medical, cat. no. 309661,

- Needles (18G; BD Medical, cat. no. 305195,

Fabrication of Patterned silk films

- Aqueous silk solution, 8% (wt/vol)

- Polydimethylsiloxane (PDMS; Sylgard 184, Ellsworth Adhesives, cat. no. 184, SIL ELAST KIT 0.5KG,

- Diffraction grating: size, number of grooves and depth of grooves can change (e.g. Edmund Optics, 600 grooves mm−1, 1,000 nm ruled diffraction grating, 50 × 50 mm, cat. no. NT43-208,