Team:BostonU HW/Results


Neptune paints a bright future for microfluidics
Benefits of Neptune to Synthetic Biologists

Neptune Deliverables

  • Liquid Flow Relations & User Constraints File
  • μShroom Mapper
  • Piston Rod Mechanical System for Valve and Dispenser Operation
  • MEC Board Integration for Modular Hardware Baseboard
  • Maped Mechanical Motion for Servo-Syringe Combinations
  • Scalable Electronics Designed to Support up to 200 servos
  • Constant Flow Rate Mapping for Servo-Syringe Combinations
  • Parametric 3D Printed Parts for Supporting Hardware Infrastructure
  • Evaluated Servo-Syringe Combinations
  • Arduino Mega Firmare to Control Servos for Valve and Dispenser Operation
  • User Interface to Specify Microfluidic Design
  • User Interface to Design Microfluidic Design
  • User Interface to Assist in the Build of Microfluidic Systems
  • User Interface to Guid a user through Assembly of Microfluidic Systems
  • User Interface to Control Microfluidic Systems by Communicating with Arduino Mega to Operate Valves and Dispensers
  • Packaged Software Tool for Installation
  • Verification of Neptune Tool Through Chip Design

To read more detail on each of these deliverables and who is responsible for their contribution, please visit the Attributions Page.

Considerations for Replication | Neptune is built to be modular, accessible, parametric, and expandable.
All of our materials are Open Source. This includes our software tool Neptune, our parametric 3-D Print (STL) files for the microfluidic and hardware infrastructure, and our firmware used to control the valves and dispensers of our system. If an individual wishes to use, modify, or reinvent our software, firmware, or hardware, all of the material to do so is readily available to them to download at their convenience from our public GitHub repository. Also, any of our supporting software tools (including Cura and OpenScad), are free. Users can download any of these resources using the links below.

To ease the use of our tool, Neptune offers several features to the user. First, the user could simply email the developers, or visit our Github page where there would be instructions on how to get started, and some documentation. This would include what the user would need to download, and the steps to get Neptune running on the biologist's computer.

When the user first enters Neptune, they could also go through a guided tour using the 'Tour' button on the dashboard page. The guided tour would step through the entire application to show the user what they need to do to make their first microfluidic chip from top to bottom.

Otherwise, the user can visit our iGEM wiki page where they can view more documentation, tutorial videos, and so on. They could also reach out to the synthetic biology community to talk to other biologists and how they used Neptune for their research experiments. This interaction using Neptune would enable biologists around the world to share their ideas, get feedback, and progress the advancement of science.

All of our STL files used for 3-D printing hardware infrastructure are parametric. If the user decides to use a different servo than that which Neptune recommends, he or she may simply enter a few measurements into the parameters listed at the top of the provided files and the designs will update automatically to reflect those changes.

Our software is designed to convert a mL amount to be dispensed into a PWM command to be sent to the arduino such that an even dispense rate is achieved for fluid movement through the microfluidic device. This conversion, however, is dependent on the specific servo/syringe combination the user has implemented. If the user decides to use a different servo/syringe setup than what is recommended by our system, he or she may still use our dispense conversion algorithm to control their system as it is also completely parametric.


Our Hardware system is highly adaptable for both small and large system requirements. Neptune is capable of running up to 200 servo/syringe combinations at once, fulfilling the need for the most demanding microfluidic system. This number is calculated by finding the bottleneck in data transfer from the computer to Arduino, and the transfer rate from Arduino to motor controller shield. Processing time in both the computer and Arduino are comparatively negligible.

Transfer to Arduino: 115,200 bits/second, 14,400 bytes/second Transfer to motor controller: standard mode of I2C: 100,000 bits/second, 12,500 bytes/second Bytes required for one command: 12

Therefore the maximum theoretical number of commands that can be sent at once is 12,500/12 = 1040. Including a safety margin of over 5x to ensure that all servo/syringe combinations can move 5x per second to ensure smooth motion all at once, Neptune’s set maximum is 200 servo/syringe combinations.

Neptune transforms the build area of a desktop CNC mill into that of an entire machine shop, and beyond. By milling square, modular components with pre-drilled holes for easy mounting Neptune can span a build area of one 4.2”x 4.2” square to hundreds of feet in any direction. This modularity, in addition to enabling huge build areas, allows for custom baseboard configurations to fix each project’s individual needs. The pre-drilled holes ensure proper component alignment and spacing, further adding to Neptune’s ease-of-use.

Future Plans for Neptune
Neptune has the ability to guide a user through designing, building, and controlling a microfluidic system. Further development on this functionality will incorporate the automation of controlling an experiment in a microfluidic chip through Neptune. We plan to design a scheduling language which Neptune will use to schedule events such as opening or closing a valve or dispensing a certain amount of liquid at specific times. The user will be able to utilize this functionality in a graphical, intuitive way. This will enable a scientist to run a completely automated experiment through Neptune’s tool chain.

In order to allow a more precise control over a microfluidic system through Neptune, we plan to incorporate sensor data collection into the GUI. When running an experiment, automated monitoring of factors such as fluorescence, temperature, and pH can allow for a more intelligent experiment scheduling. For example, if cells in a cell trap need to reach a certain level of fluorescence before a nutrient is washed over them, our future plans for Neptune provide an interface where a biologist can monitor this fluorescence using sensors (such as those manufactured by Atlas Scientific), and schedule his or her program to make intelligent decisions to dispense nutrients based on the current level of fluorescence of those cells.