Volume Verified Pipetting is now available on our air based pipetting channels of our independent tips (i8 VVP Arm), Fixed-8 and 96 VVP Head. This VVP flow sensor technology allows our independent channels, fixed-8 or the 96 channel head, to monitor and control each channel to verify volumetrically each liquid transfer in addition to the ability to aspirate and dispense different volumes in each channel. Yes, you are reading this text correctly, the 96 VVP Head has independent AND verified volumes in EACH tip!

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Through the implementation of Volume Verified Pieptting (VVP) technology in the i8 VVP Independent arm and 96 VVP Head, it is now also possible to directly measure liquid transfers volumetrically creating a final validation that methods are accomplished as programmed.  This takes the guess work out of pre-validated methods running water, reagents with dye or multiple dispenses over a balance to 'average out' how individual liquids may be handled.  Now, validated reports are the standard with actual volumes recorded at each liquid aspirate/dispense activity and stored in the same database as all the other standard sample tracking information; like sample bar codes, tip and plate bar codes, reagent lot number, etc.

Air Based System

The Air-driven Pipetting Heads with integrated flow sensor are suited for liquid handling in microliter to mililiter volume range. This product has been designed to fit a wide range of applications where action validation and process surveillance is required. The use of a dedicated MEMS flow sensor at the pipetting site allows complete validation of aspiration and dispense actions in real time, as well as providing clogging detection and other process monitoring information.

The Pipettor operates with a pressure/vacuum source, typically in the range of ± 200 mbar gauge for aspiration/dispense pressure. The pressure controller further acts as System Controller by providing a single port access from the host computer. Integrated high level coordination between the pressure source and the pipetting unit allows an efficient and rapid integration of the unit onto our customer's automated platforms.

The video below shows monitored flow rate of the liquid on the left hand side y-axis, time on the x-axis and total volume on the right hand side y-axis.  At time zero, the system opens a valve to allow vacuum to pull liquid into the tip.  Both the pressure and flow rate are monitored giving the actual cumulative volume entering the tip.  As the volume requested is reached, the valve closes ending the aspiration at the volume requested.  In this system, the viscosity and temperature are automatically accounted for by the flow rate so there are no parameters such as liquid classes to set or calibrate, it is all done automatically... volumetric pipetting on an automated workstation.

Benefits:

• VVP allows the active 'volumetric' monitoring of pipetting leading to more precise and validated liquid transfers
• Factory calibrated 'out-of-box' pipetting
• Reproducibility from tip to tip and platform to platform
• Uses same technology as hand held pipettes that are the standard in the lab
• Active and continuous anti-drip and leak monitoring
• No cross contamination with the use of disposable tips
• Liquid level sensing with standard clear tips
• Actually see the liquid in your tips, as opposed to black poly carbonate tips

Advantages over microliter/milliliter liquid based systems:

• No liquid class development
• No dilution effects from fluid filled microliter/milliliter systems
• No hydraulic system fluid, reservoir or liquid lines throughout to maintain and purge daily
• No hand tightened fittings
• Easy service diagnostics
• No remote syringes for liquid handling
• No need for expensive 'black' tips to sense liquid levels

Advantages over other air based systems:

Verified Volume Pipetting - VVP

Dynamic Devices specializes in a unique technology for accurate dispensing of microliter and milliliter quantities of liquid.  A miniature flow sensor allows real-time measurement and control of aspirated and dispensed volumes. Next to a high accuracy, this technology provides a continuous monitoring of system functionality for added reliability and performance verification.

High precision, reliability and complete volumetric validation are achieved by using MEMS flow sensor real-time volume measurement and feedback control independent of the sample liquid properties.

Liquid transfers between 0.5 and 1000 uL with a viscosity between 0.5 and 10 cP are all handled automatically within the standard volume system.

All systems provide real-time measurement, reporting and validation of aspirated and dispensed volumes.

Flow Sensor Technology

Dynamic Devices implements the Seyonics Senor Controlled Pipetting within our i8, Fixed-8 and 96 Head.  The Seyonics flow sensor is based on the measurement of the pressure differential across an integrated fluidic restriction. A silicon chip consisting of piezo-resistive pressure sensors, connected by a micro-channel, forms the actual flow sensor device.  The signals available are inlet and outlet pressure and fluid temperature.

In order to address different flow ranges, a family of sensor devices with different restriction geometry has been developed. The tree basic output signals, together with the calibration factor for the restriction and the temperature corrected viscosity of the liquid, are used to calculate the volumetric flow.

The MEMS device is mounted onto a ceramic substrate together with 2 ASICs providing pressure signal amplification and compensation over the temperature range.

After appropriate manufacturing calibration, the sensor mounted into a plastic manifold.

Fluidic connections to the sensor are made through a custom housing with a 9x9mm footprint for implementation in multi-channel systems that fit the standard micro titer plate format.