1

3D Printing Vegemite and Marmite: Redefining ‘Breadboards’

Charles Hamilton University of Wollongong Primary Supervisor: Prof. Marc in het Panhuis E-mail: [email protected] Takeaways 2 - Rheological properties of materials are critical to different aspects of FLM -These properties are (generally) highly tunable

- FLM and pre-existing commercially available food products can be used in unique and creative ways – Food today can be more than just sustenance

- Attractive food presentations - Edible electronics devices - Scientific outreach & learning activities

Source: google search & vegemite.com.au 3D Food Printing 3 Additive manufacturing process where a material is deposited layer-by-layer onto a substrate to produce a 3-dimensional object

Coined ‘Food Layered Manufacturing’

Sun et al 2015 - Useful in addressing malnutrition, dysphagia, specialized dietary requirements, and more - Numerous printable materials History of Vegemite 4 1922 – Dr. Cyril P Callister developed a food spread from brewer’s yeast for a company soon be Kraft Foods

This ‘Pure Vegetable Extract’ marketed for its ‘delicious’ taste was not successful initially (Marmite was already widely established in Australia)

Renamed ‘Vegemite’ during a competition and eventually gained popularity

Vegemite.com.au History of Vegemite 5

-Staple during WWII and recommended by doctors to patients in the early 40s

-Exponentially grew in popularity

-Iconic Australian breakfast spread, full of Vitamin B and nutrients

Happy Little Vegemites Commercial

-22 million jars are sold every year

Vegemite.com.au Printers Used 6 Pneumatic v. piston driven system, each has their advantages

BioBot Custom CNC based Printer -Commercially Available Pneumatic -Zaber Linear Actuators System (Piston Driven) -Heated Jacket -Gcode written by user -Meant for bioprinting -Gcode from slicing software

Biobots.io Printing at Different Viscosities 7

Viscosity changes with temperature

Greatly affects integrity of printed structure Vegemite 35 Marmite

How can we predict this rather than trial & error? 30

25

20

Pa s Pa 15

25°C 10

5

0 0 5 10 15 20 25 30 35 40 45 Temperature (C)

45°C Rheological Properties 8

Power Law Fluid Rabinowitsch-Mooney Equation

η = viscosity γ = shear rate Q = volumetric flow rate K = consistency (viscosity at γ = 1) n = power law index n = power law index (non-newtownian nature) r = radius Rheological Properties 9

How to avoid this

Bingham Model

Yield Stress – How much pressure is required to make the material flow like a σ = shear stress liquid

σy = yield stress η = viscosity Analogous to pressure needed to squeeze γ = shear rate toothpaste out of a tube Attractive Food Presentations 10

-Fun and festive, useful for celebratory events -Can encourage children to eat a nutritious breakfast It’s Electric! 11

Vegemite and Marmite are inherently conductive

Can print edible circuits! Edible Electronics 12 Useful for GI tract monitoring, disease screening, and more

Material Conductivity (mS/cm) vegemite 20 ± 3 marmite 12.8 ± 0.5 Aeroplane jelly 154 ± 19 alginate/gelatin 194 ± 14 gellan 204 ± 19 gum/gelatin

A. Keller et al 2016, MRS Proceedings Haptic Sensing 13 Gellan gum/ Gelatin Electrodes

Gelatin

Dielectric Compressive 30 30 23 25 25 18 Cycle 1

20 20 (pF)

0 13 Cycle 2

C 15 15 stress(MPa)

- Cycle 3 8

C C 10 10 Cycle 4 5 5 3 (pF) Capacitance Cycle 5 0 0 -2 0 5 10 15 20 25 0 1 2 3 4 5 Cycles Pressure kPa Pressure vs capacitance for five loading and Cyclic loading response of an edible pressure sensor. unloading cycles. A. Keller et al Unpublished FLM for Outreach 14 Everyone can relate to food!! Vegemite Demo at the 2015 UOW Big Ideas Festival Electronics for Breakfast Youtube Video

Outlet for introducing scientific concepts to the public in a digestible manner Encourages students into STEM fields Acknowledgements 15 Supervisors: Prof. Marc in het Panhuis (Primary) Prof. Gursel Alici Prof. Geoff Spinks

ARC Centre of Excellence for Electromaterials Science Intelligent Polymer Research Institute UOW School of Chemistry & Soft Materials Group

Chris Richards & Dr. Holly Warren

Hamilton, C.A., et al., 3D printing Vegemite and Marmite: Redefining “breadboards”, Journal of Food Engineering (2017), http://dx.doi.org/10.1016/j.jfoodeng.2017.01.00830, 2017]. Questions? 16