Sub-Microliter Piezoelectric Dispensers

The GeSiM microdispensers don’t touch the surface to spot on, which minimizes damage to the surface and maximizes spotting flexibility. The dispensers (also called "pipettes" or "jets") follow the drop-on-demand principle, i.e., a drop is released exactly when the piezo ceramic actuator is triggered. This results in the bending of a silicon diaphragm behind the actuator and this in turn leads to a compression of the liquid inside the “pump chamber” and hence to the ejection of a droplet from the nozzle. After this, the ceramic returns to its initial state and the dispenser is refilled with liquid from the inlet. No valve is involved in this process.

The following liquids where successfully dispensed using GeSiM's standard piezoelectric pipettes/dispensers:

  • Acetic anhydride
  • Acetone, and all mixing ratios with water
  • Acetonitrile, and all mixing ratios with water
  • Betaine (N,N,N-trimethylglycine, < 1 M)
  • Chloroform
  • Cyclohexanone
  • Dextrane solutions
  • Detergents (e.g. 2 % Triton X-100 or Tween-20)
  • Dichloromethane/trifluoroacetic acid (98:2)
  • N,N-Dimethylformamide (DMF), and all mixing ratios with water
  • Dimethylsulfoxide (DMSO), and all mixing ratios with water
  • 1,4-Dioxane, and all mixing ratios with water
  • DNA (oligos or PCR products < 3 mg/ml, 4 kb plasmids < 1 mg/ml)
  • Ethanol, and all mixing ratios with water
  • N-FMOC-Ile (200 mM in DMF)
  • Glycerol (< 50 % in H2O)
  • Iodine (in THF/pyridine/H2O 3:75:20:75)
  • Isopropanol, and all mixing ratios with water
  • MALDI matrix (α-cyano-4-hydrocycinnamic acid in NMP, 3-HPA in 20 % acetonitril)
  • Methanol, and all mixing ratios with water
  • 1-Methyl-2-pyrrolidone (NMP), and all mixing ratios with water
  • 1-Methylimidazole (16 % in THF), and all mixing ratios with water
  • NaCl (< 3 M)
  • PBS (phosphate-buffered saline, standard protein printing buffer)
  • Phosphoramidite (T-CE in acetonitrile)
  • Polyethylene glycol 10000 (PEG, < 5 %)
  • Polymers (P3OT 1 mg/ml in trichloroethylene or Chlorobenzene, PEDOT:PSS 0.14/2.56 %)
  • Proteins (< 1 mg/ml, < 10 mg/ml under certain precautions)
  • SSC (saline sodium citrate, 3x)
  • Tetrahydrofurane (THF), and all mixing ratios with water
  • Tetrazole (in acetonitrile)
  • Toluene
  • Urea (< 7 M, humidification recommended)


The multi-dos is the control device for up to eight independent dispensers and connects to the serial interface of your computer. The PC software mds8 supports the control of all dispensing parameters (voltage, frequency and pulse width) individually for each piezoelectric dispenser. The dispensers can be driven in start/stop mode (continuous dispensing/pumping) or in burst mode, with a programmable number of droplets. External triggering is also supported.


The micro-dosage heads can be filled manually using a syringe. To automate liquid handling, we recommend to use a diluter system consisting of a computer-controlled syringe pump with three-way valve. This allows one to automatically flush the dispense head with system liquid (water) and automatic take up sample through the nozzle or feed the sample from the inlet side.


This is an indispensable tool to optimize the function of your dispenser. Please note that an extra plug-in board in the multi-dos is needed to control the stroboscope, thus reducing the number of possible dispensers.

  • Visualization (still image) and qualitative assessment of the droplet generation
  • Quantitative determination of dispensing parameters
  • Display with extra video monitor or frame grabber and PC software


We offer reservoir vessels, tubes and filters for an easy setup of your experiment. With these add-ons, the connection of your piezoelectric dispenser with a syringe system becomes easy. In-Line droplet calibration is available with the GeSiM.

Basically piezoelectric microdispensers work well in a certain viscosity range (up to 5 mPa·s). Substances of higher viscosity can be succesfully dispensed when...

  • Piezo-electrically driven microdispensers with the ability to eject droplets down to 0.25 nanoliters
  • Micro dispensers are enclosed by a heater element
  • Various types with different fluidic and electrical connectors available

Temperature Controller

  • Accuracy of the displayed process value < 1.0 K at 100 °C
  • Event input for changing function and set points
  • PID controller with self-tuning option
  • Input sample rate: 10 Hz

Dispensable Media

  • Adhesives ET UVO-114, ET OG169, ET 301-2, Epoxy Technologies
  • Delo Photobond® 4302
  • Glycerol, up to 100% glycerol
  • Liquid Crystals Merck Licristal ZLI-2222-100 (approx. 12 mPas) and MLC-6681 (approx. 95 mPas) at 43 °C
  • Byllux 6308 (Nano-Tip-HV, Byllux 6508 (Nano-Tip-HV, Pico-Tip)
  • NOA74, NOA75 (Nano-Tip-HV, Pico-Tip)

GeSiM’s standard piezoelectric micropipettes/microdispensers can dispense liquids with viscosities of about 5 mPa·s (5 cP). Slightly higher viscosities may work but this must be tested for each liquid.

Adhesives often have high viscosities. There are two ways to dispense them: the design of the microdispenser can be optimized for higher viscosities or the viscosity is reduced by heating. GeSiM microdispensers should not be heated to more than 120 °C, i.e., the viscosity of the liquid should not exceed 5 mPa·s at 120 °C.