This week is the final week of the class. It's been a journey and we've explored many systems in our quest to create functionally graded material. Here's a look back, where we are today, and where we hope to get to with the systems we've built.
The original goal was to achieve functionally graded clay with three components: an earthen material, a bacteria, and air. We imagined a three tubed system that would hold all of the various components and would then be selectively mixed by an auger end effector.
We broke every part of each system we built. From the polycarbonate tubes with pressure build up, the plunger, and a half inch steel rod among others.
We also tested three different systems: a plunger base paste extruder, a compressed air system, and finally a peristaltic pump dual material system. Which brings us to the final week! Our goal this week was to extrude two materials from one nozzle and then alternate between flows.
PERISTALTIC MIXING
Plunger System
Bending Threaded Rod
Cracking Polycarbonate Tube
Torn Through Plunger
Foam and Clay Output through Compressed Air
Peristaltic Pump Dual Material System
The Setup
Debugging the system
Colors Added to Evaluate
Material Interface
Laminar-like Flow
Laminar-like Flow
Multi-Material 2D Extrusion
Alternating Flows
Laminar Like Flows
Clay Slip
Controls
Pumps
Foaming System
KEY QUESTIONS
EVALUATING SUCCESS
WE MADE
TEAMWORK
Can we take air and bacteria and create printed structures that are both lightweight and slowly increasing in strength over time?
Can we create "just in time" mixing of materials with significantly different densities at the end effector of a 3D printing system?
Can we do so in a scalable fashion?
Can we create a system that is modular and accessible/affordable?
Robustness and reproducibility.
Accessibility and affordability.
Scalability and flexibility.
1. A stepper control interface and simple driver configuration that we used for all experimental setups.
2. A high volume benchtop paste extruder with the torque to supply thick earthen materials to an end effector.
3. An auger system with interchangeable inputs, nozzles, and auger screws which can be easily adapted to different machines.
4. Low cost foam generator which produces consistent fine cell foam for use in cellular air entrained earth, concrete, or other paste like material.
5. An extremely low cost 3D printed peristaltic pump that can be scaled to different motors.
6. A dual peristaltic pump mixing assembly for multimaterial extrusion and switching.
7. Low cost benchtop bioreactor with integrated pump, impeller and control for both.