MicCell – Customizable Tool Kit for Microbiology
Microfluidic systems may integrate fluidic, electronic and optical functions. Being a valuable tool in routine use prototyping can be challenging and expensive. When diagnostic cartridges needs to be optical transparent they often feature hot embossed microplastics. The manufacturing processes than require expensive production machines and layout specific casting tools.
The GeSiM MicCell on a microscope stage (left), attached to a FluidProcessor (mid), controlled by GeSiM Fluidics app (right)
For R/D purposes the MicCell combines an affordable casting process using PDMS and a convenient mechanical setup for quick replacement of the used PDMS channel plate. The mechanical frame of the MicCell fits on standard microscope stages.
Please also refer to the Microfluidics section for silicon-glass flowthrough cells and complex microfluidic instruments.
PDMS Flow-Cells: The “Do-It-Yourself” Way
Core of the MicCell is an optical transparent PDMS (Polydimethylsiloxane) chip with a user specific microfluidic channel layout. It is accomplished by “channel spacers” for fluidic interconnections and calottes/ polycarbonate frames for mechanical adaptation to standard microscope systems.
The “MicCell-Process”: Preparation of the PDMS-CP “Channel Plate” (Left); Position of the PDMS-CP during usage (Right)
The disposable PDMS chip can be done by the customer using the included casting set. It is easily replacable, therefore microfluidic experiments can be done at affordable costs.
Standard sizes for the PDMS channel plate are:
- 22 x 22 mm
- 22 x 50 mm
- 25 x 75 mm
The PDMS channel plate goes in between the Polycarbonate carrier and the calotte and gets sealed by a standard glass lid. Glass lids wih electrode structures on the inner side are available on request.
On top of all, the MicCell channel plate carrier can be completed with other microfluidic parts, tubes, filters, bottles, syringe systems and an operation software. Move on to FOILS VS. PDMS for more information and downlaod the full MicCell catalogue on the bottom of this page.
Casting Set for PDMS Channel Plates
The casting set mainly comprises the casting station, Polycarbonate carriers, liquid PDMS and syringes. In addition, you will need a “Master Chip” introducing your particular channel layout.
Casting set for PDMS channel plates (CP)
Injection of the liquid PDMS into the casting station
The master chip is made from Teflon coated silicon and made at GeSiM on request. Basically we accept any layout provided by a CAD drawing; a set of typical channel layouts is on the shelf. Please ask.
Foil Based Flow-Cells: Made to Order
Alternatively GeSiM offers customized microfluidic systems made of adhesive foils that are cut by different technologies and assembled in our factory. They can be ordered in small and large quantities, thus can be used as disposable, and snugly fit in the GeSiM MicCell chamber. They are an attractive alternative to PDMS channel plates. GeSiM is currently redesigning the BSyS robot to produce them automatically.
Systems from glass are also available, please inquire.
Intricate multi-layer layouts can be achieved so that numerous applications, e.g. point-of-care diagnostics, become feasible. Interesting accessories are membranes with defined cylindrical nanopore geometries from Oxyphen AG, produced by beaming with energetic heavy ions. This has e.g. allowed the safe encapsulation of genetically engineered yeast cells in biosensors for anthropogenic pollutants in wastewater (Schirmer et al., 2018, 2019; Günther et al., 2019).
“Track-etched” membrane (Oxyphen GmbH) placed on a cut foil (darker) with round hole and channel. The speckles are the pores.
Measurement of Tiny Flows
The GeSiM flow sensor has been designed for flow rates in the range of 0…100 Microliters per minute. It is a thermocalorimetric sensor measuring the heat transfer in a very tiny chamber. The fluid sample is negligibly heated whereas the surroundig temperature distribution is monitored.
As larger the heat transport through the chamber as more precisely the measurement result will be. In other terms, as more time is allowed for a single measurement as better the accuracy.
The sensor can be used along with the MicCell Fluid Processor (See tab FLUIDPROCESSOR) but is available for standalone operation too. The sensor is cascadable, it allows to measure several independent fluid flows simultaneously. Up to four stacked sensors can be managed by a single controller. The controller connects to a PC through serial interface, a dedicated software displays the measurement result.
Fluid automation at the benchtop format can expedite your daily work in the lab. Whether you operate at the micro- or macroscale, the GeSiM FluidProcessor (FP) is your personal central processing unit for liquids and gasses. The FP is a horizontal rack with standardized slots for functional modules. Each FluidProcessor is custom made to order, configured for your particular application. The FP builds up from a library of functional modules, thus the users will get exactly the hardware for their special purpose. The ability of post-sales reconfiguration adapts your FluidProcessor to changing tasks, securing sustainability and investment protection.
The FluidProcessor hooks up to your microfluidic system. The optional combination with a GeSiM “MicCell” flow-cell (see tab FLOW-CELL) results in a fully automated microfluidic setup for many applications in life science and chemistry. Standard fittings (Upchurch Scientific and others) allow an easy connection to other flow-cells, e.g. from Microfluidic Chipshop.
The basic setup of a FluidProcessor with MicCell flow-cell and control computer
The FluidProcessor and GeSiM Robots
The GeSiM FluidProcessor and the GeSiM robots share the same automation platform.
Whilst the FluidProcessor operates microfluidic cartridges with openings, semipermeable lids, open wells on deck of a GeSiM instrument, it can interact with tool heads for pipetting, 3D printing, or camera inspection installed on the robot. 3D Printing of organoids in chambers of fluidic cartridges, sealing, cell cultivation and camera inspection can be done at one place without moving sensitive targets through non-sterile environments.
Library of Functional Modules for the GeSiM FluidProcessor
How to get hold of your individual GeSiM FluidProcessor?
- Contact GeSiM with your application, drawings, charts, descriptions,
- Select functional modules of interest,
- GeSiM designs your FluidProcessor, completed with internal/ external tubes, filters and reservoirs. Fittings are available for GeSiM flow-cells as well as for your own microfluidic components. A detailed tubing scheme is available for the customer before your FP leaves our manufacturing facility.
What is available for the GeSiM FluidProcessor?
- Syringe pumps, with and without selector valves for precise displacement dispensing
- Membrane pumps for continuous liquid flow,
- Two- and three-way valves
- Pressure regulators for different pressure ranges
- Vacuum generator
- Liquid-level sensors for external reservoirs
- External reservoir bottles of different volumes (250 mL to 1,000 mL)
- Pneumatic extruder unit with cooler/ heater for 10ml cartridges,
- Drivers for piezoelectric drop-on-demand dispensers
- Drivers for chip-based micro-flow sensors (Measurement range below 70 µL/min)
Please ask for the MicCell catalogue with detailed information on all available functional modules.
Explore the Inside of a FluidProcessor
Example configuration of the MicCell Fluidprocessor (internal tubing not shown).
From left to right:
The FluidProcessor combines fluid handling modules in an application specific manner. The available modules at standardized width plug into the slots of the instrument. Modules will occupy either a single slot or multiple slots. Modules slide in on front or rear panel, depending on their function. Each FP comes with a CPU, power adapter, regulated fans and Ethernet based backplane. It hooks up to the control computer by a usual LAN cable.
Syringe pump module with selector valve: Different syringe sizes are available, flow rate ranges from 0.0025 mL/min to 261.6 mL/min. Enables precise and bidirectional liquid flow from reservoirs to flow cells.
Double 3/2-way valves: TwinPower rocker solenoid valves with separating diaphragm. They offer pressure resistance up to 2 bar and high back pressure tightness with excellent cleanability. Tube connectors ¼“-28 UNF (female) for easy hook-up to external flow cells.