3D printing is a rapidly growing field that is becoming increasingly popular for constructing living tissues. Bioprinters have been used to print complex combinations of biocompatible hydrogels and cell populations with great accuracy. A layer of viscous biocompatible material is applied with one print head and cross-linked with a UV light source. Cells suspended in a bio-ink are then deposited on top of this gel with a separate print head. This technique requires a unique print head for each different hydrogel or cell population, reducing both the print speed and maximum print size, while drastically increasing complexity. 3D printed hydrogels must also be UV crosslinked with a separate light source, which further increases print time and can have a negative effect on cells.
Both of these issues can be solved with the addition of microfluidic fluid routing devices. A single device the size of a glass slide could handle all the fluid routing for multiple hydrogels and allow the printer to easily switch between them. By changing the pressure of individual fluid reservoirs, the printer could quickly switch between different materials without requiring extra heads or switching steps. This technique also simplifies the coding of the printer, increases maximum printable area, and reduces the time spent switching materials. The incorporation of a microfluidic print head also allows the printer to crosslink the hydrogel material within the printhead. In this way, hydrogel material could enter the microfluidic chip as liquid, be crosslinked by a directed UV beam, and exit the printhead as a solid gel. This would allow the printer to create strands of aligned collagen with high precision, which is very useful for cell and tissue culture because it is analogous to how collagen is structured in the body. The addition of a microfluidic chip would also allow the 3D bioprinter to create more complex structures by harnessing techniques like hydrodynamic focusing. Flow focusing would allow cells to be printed within channels of hydrogel, allowing the printer to create more complex structures.
The current prototype has a functioning microfluidic printhead with X , Y, and Z control. The next steps for this project will be generation of a 3D structure and incorporation of live cells into the hydrogel. Further stages of the project could include incorporation of multiple hydrogels to allow for sacrificial components, prototyping nanocomposite gels to improve mechanical properties, and addition of UV crosslinking functionality to the printer.
Project Title: 3D Microfluidic Bioprinter
Project Number: P20677
Start Term: 2019 Fall
End Term: 2020 Spring
Cory Stiehl, firstname.lastname@example.org
Vinay Abhyankar, email@example.com
Sponsor (financial support):
Vinay Abhyankar, firstname.lastname@example.org
(Left to Right) Cody Lentz, Anthony Aggouras, Luc Chartier, Grant Korensky, Nicholas Lee, Shriji Patel, Charif Elmoussaoui
|Nicholas Lee||Biomedical Engineering|
Chief Executive Officer/ Engineer (project leader)
|Shriji Patel||Biomedical Engineering|
Chief Financial Officer/ Engineer (purchasing)
|Anthony Aggouras||Biomedical Engineering|
Chief Operating Officer/ Engineer (facilitator)
|Cody Lentz||Mechanical Engineering|
Chief Technical Co-Officer/ Engineer (printhead lead engineer)
|Grant Korensky||Mechanical Engineering|
Chief Communication Officer/ Engineer (project coordinator)
|Charif Elmoussaoui||Electrical Engineering||Chief Documentation Officer/ Engineer (project documentation)||email@example.com|
|Luc Chartier||Electrical Engineering|
Chief Technical Co-Officer/ Engineer (controls lead Engineer)
Work Breakdown: By Phase
MSD I & II
Customer Handoff & Final Project Documentation (Verification & Validation)
Work Breakdown: By Topic
Use this space to link to live/final documents throughout the project. Your team should customize this as-needed, with input from your guide and customer. The example below will address most of what most teams need to capture.
Presentation & Dissemination
Communication & Minutes
Pugh Concept Selection
Design Review Documents
Imagine RIT Exhibit
|Movement||C1||Move print head in X, Y, and Z direction||Critical (9)|
|Printer Capabilities||C2||Ability to extrude crosslinked hydrogel||Critical (9)|
|Printer Capabilities||C3||Ability to embed cells in print||Critical (9)|
|C4||Repeatability of fiber diameter||Moderate (3)|
|Biocompatibility||C5||Compatible with breast cancer cells||Moderate (3)||Cell most likely used for testing|
|Thermal Control||C6||Ability to control bed temperature||Critical (9)||37C||Must be kept within 2 degrees of target|
|Fluid Dynamic Control||C7||Ability to control flow of printed material||Moderate (3)|
|C8||Easily swapped interchangeable printhead||Moderate (3)||"Easily swapped" meaning by anyone in a timely manner|
|Printer Capabilities||C9||Prints small prints in minutes||Moderate (3)|
Extrude single strands in a timely manner in the case. The printer is used for demo purposes.
|User Interface||C10||Can be operated by junior/senior level undergraduate in Biomedical Engineering||Not Critical (1)|
User friendly without an extensive background or tutorial on using the printer.
|Specifications||C11||Machine footprint must not exceed 18"x 18"x 24"||Critical (9)|
|E1||Capable of moving print head throughout entire print space (##X##X##)||meters|
|E2||Extruded material achieves minimum viscosity of ##.##+/-## or poisson ratio of ####|
|E3||incorporate cell seeding density of ## per uL|
|E4||maintain 60% cell viability after 48 hours of cell culture.|
|E5||Maintain printing bed temperature at 37 +/- 2 celsius||°C||35||37|
|E7||Relative error of calculated to actual flow rate is less than 15%|
|E8||Print head change done in less than 10 minutes||minutes||0||10|
|E9||Strand diameter should be 2 millimeters at most||millimeters||0||2|
|E10||Standard deviation of different fibers|
|E11||Able to print constructs of size 10mm X 10mm X 1mm||mm||10 X 10 X 1|
|E12||Print max size print in less than 15 minutes.||minutes||0||15|
|E13||Automatic shutoff/emergency off switch|
|E14||Compatible with common slicers (g-code files)|
- Be sure to include any relevant sponsor acknowledgement throughout your site.
- Acknowledge any other support you have received from people at RIT or elsewhere.