Fluid Metering Inc. Blog

As an engineer, having a way to dispense fluids through a non-contact tip in medical diagnostic and other devices could potentially be not only life changing, but life-saving. The current options for dispensing require contact- mostly consisting of a submerged tip or use of the touch off method. Neither of these options are desirable due to either cross contamination possibility, non-repeatability, or lack of accuracy. An ideal method to solve this issue would be a pump with non-contact dispensing capabilities.

Solutions to dispensing a small amount of fluid (typically less than 10 microliters) have previously been few and far between, aside from the limited options listed above. You are probably looking for a better pump solution that allows you to dispense fluids in an accurate and sterile way.

Fluid Metering's Solution to Non-Contact Dispensing

Fluid Metering's patent pending non-contact dispensing methodology suspends the tip over air and still accurately and precisely dispenses small amounts of fluid, making sure the fluid breaks away cleanly, repeatably, and to the desired location.

This is especially beneficial for medical devices, such as diagnostics which might need to dispense a fluid to start a reaction. The non-contact dispense method produces a result that is very accurate in a specific location to interact with the desired media and provides the level of delicacy needed for these types of devices.

This non-contact dispensing methodology can be used in various other pieces of medical devices as well. FMI developed this methodology to be able to get to the outcome of non-contact dispensing and can work with you to incorporate it into your machine.

How Would We Implement This in Your Device?

There are four main areas we look at when implementing non-contact dispensing into a device:

Tip

• We would need to review what kind of tip you are going to use. Ideally, this would be a hydrophobic tip so as not to attract the fluid.
• We would also need to make sure the tip materials are compatible with the fluid you are dispensing.
• Finally, we would need to review the gauge size of the tip. This is especially important when it comes to the speed the fluid is dispensed at. For example, if the tip size is too large, the fluid will not break away very cleanly, leading to dispense volume variability. If the tip size is too small then the fluid will jet out too forcefully and cause splashing. A correct tip diameter is critical for repeatable dispenses while minimizing the potential for splashing.

Tubing

• The internal diameter and material of the tubing that goes from the pump to the dispense tip is extremely important. Any air in the line can act as a cushion, which will impact how the fluid dispenses from the tip.
• An ideal material for the tube is hydrophobic with a rigid wall. If the tube material is too flexible, pressure from the dispense will cause the tubing wall to expand, which will in turn cause pressure fluctuations in the tube, leading to inaccurate dispensing. Generally, a small internal diameter is desirable.

Pump Motor

• The motor acceleration (the pump itself) is very important to evaluate as well. From standstill to desired speed needs to be reached very quickly to make sure the required volume is achieved every time.
• Deceleration is also very important, for the same reasons. The pump needs to stop just as quickly as it starts up for precision purposes.

How the Pump Head is Primed

• If there is any air in the pump head, it throws the entire system off and makes it almost impossible to dispense small volumes over air.
• Priming is important from the initial start of the pump to ensure there is no air in the tubing. Any excess of air will decrease the accuracy and precision of the pump as well as inhibit the non-contact tip methodology.

Learn More About How Fluid Metering Can Help

At Fluid Metering, we believe that you shouldn't have to sacrifice for less than the best, which is why we created the non-contact dispense methodology to be used in dispensing less than 10 microliters of fluid.

Our experts will be there through every step of your journey to help you select the right pump and tip for your individual needs. Here is how we can help:

1. Reach out to our business development experts who can help guide you through the beginning process to ensure you are working with our engineers who specialize in your exact needs.
2. From there, you will have a direct line to our engineering team as we work closely together with you to develop a product based on your individual specifications.
3. The end result will be a complete fluidic solution that accomplishes non-contact dispensing for use in your medical diagnostic device or other applications. Fluid Metering is invaluable in testing for reliability to ensure that your pumps will last and provide the expected dispense volume.

Our FENYX Variable Dispense Pump (formerly FVD) is recommended for non-contact dispensing.

To get started developing your solution with Fluid Metering, contact us today.