Pico FillSystems Outlicensing Electrospray Deposition onto Small Targets





- Slides: 5

Pico. Fill-Systems Outlicensing Electrospray Deposition onto Small Targets Target Applications: q Micro. Array Applications: spraying of enzymes, metabolites, cofactors, yeast cells, antibodies: addition of up to 20 wt% of carbohydrates like trehalose to fully preserve enzyme activities after spraying followed by storage. Activities of enzymes, metabolites and cofactors are not reduced by the electric field. q Dotting of Microliter & Nanoliter Fractions onto MALDI targets q Coating Industry: spraying of liquids containing particles, polymer, etching or curing agents, etc. Spraying of viscous materials can be achieved at high temperature. Dot 0. 4 millimeter 1

Special Features q The charged droplets are pulled to the grounded substrate on-the-flight, so, no contamination of adjacent targets. q The sprayed amounts of liquid is controlled and flexible by varying the spraying time and/or flow rate. Dot-size is varied by adjusting the spray-distance. q The uniform charged droplets repel each other on-the-flight resulting in a layer of droplets instead of a droplet. This eliminates the donut effect (coffee stain effect). q The droplet spray is always directed toward grounded elements, meaning that if grounded conductive targets are embedded within non-conductive material, the droplets will only fly to these conductive targets like metal wiring or pins. q Capillaries are bendable, low-cost and may be 50 micron in outer diameter, allowing spraying of spots or lines at widths in the order of 10– 100 micron. q Parallel spraying was achieved with three capillaries (outer diameter of 150 micron) that were placed 600 micron apart. 2

Spraying Parameters Dot Size • Dot size is related to the distance between the capillary-tip and the substrate (spraying distance) • Dot size is related to the capillary outer diameter: the smaller the outer diameter, the smaller the cone size • Dot size is related to the flow rate: at low flow rates the liquid evaporates rapidly resulting in a solid dot instead of a donut like dot. • Typical dot sizes for a capillary-OD of 150 micron and flow rates of 100– 400 picoliter/second : 150– 400 microns at spraying distances of 250– 500 micron, respectively Micro. Array Applications • Flow rates: picoliters-nanoliters/second • Distance between capillary-tip and substrate (spraying distance): 200– 500 micron • Dot size microarray: 100– 400 micron at spraying distances of 200– 500 micron • Preferred capillary outer diameter: 50– 200 micron • Maximum speed of x-y-z table depends on actuators: 1. 6 inch/sec (4 cm/s) for high speed actuators Dotting of fractions onto MALDI plate targets • Flow rates: 1 nanoliter/second – 0. 6 microliter/second • Dot sizes: 400– 1500 micron at spraying distances of 500– 2000 micron, respectively 3

Spraying of Arrays of Dots A. Piston pushes liquid through syringe while electric field is applied B. Slide is moved downward to lower the electric field: spraying stops 1– 2 k. V Spray of droplets Micro. Array or slide C. Slide is moved upward and spraying resumes 1 -2 k. V Spot Slide is moved downward and sideways: typical 200 – 1000 micron Second spot is sprayed onto slide 4

Parallel Spraying Spots: 0. 6 millimeter apart 5