microcontact printing technology overview and applications for small scale patterning using PDMS (polydimethylsiloxane)

1. µ-Contact Printing System µCP2.1
short overview of the current status
GeSiM mbH, February 2008

2. µ-Contact Printing System µCP2.1
stamps with PDMS-membrane, scaled in the nm to µm range
compressed air
Stamp Chamber Stampholder Stamp Chamber
Stampframe
PDMS-Membran
nm/µm Patterns
a) Basic Mode: PDMS-membran planar b) Print-Mode: PDMS-membran deflected
SEM picture Si-Master Master in Casting Staion Casting of PDMS-Stamp PDMS-Stamp µCP-Stamping Unit

3. µ-Contact Printing System µCP2.1
stamp in touch with glass slide
PDMS-Stamp PDMS-Stamp
frame not patterned 10µm lines, 20µm pitch
PDMS - Stamp
1mm Slide
Microscope
a) scheme quot;PDMS-Stamp on Slidequot; b) photograph shows PDMS-Stamp and slide
perfectly in touch, stamp area (1x1) cm²
Remarks:
The system µCP2.1 guarantees reproducible and perfect contact between the PDMS-
stamp and the substrate.
The USER of µCP2.1 has to develope the surface chemistry to transfere samples, nano-
particles, molecules, bacteria, viruses or cells onto the biochip.

4. µ-Contact Printing System µCP2.1
accessories top view
Stamp - Washing Station
µCP-2.1 Accessories
Stamp - Casting Station

5. µ-Contact Printing System µCP2.1
µm- scaled stamps made in PDMS
Fig.1: 10µmx10µm PDMS-mesa structures, Fig.2: Donut structures, Ø 50µm, a view onto
a view onto a real stamp surface a real stamp surface

6. µ-Contact Printing System µCP2.1
foot print of µCP2.1
M 1: drive inking M2: drive stamping
M2
M1 N2-blow-dry
Stamping- Unit
Inking-Station
Stamp1 Stamp2 Stamp3 Stamp4
Dry-Station
Sample Pad
Slide-Tray
vernier drive
in y-axis
vernier drive
in x-axis
Top View µ-ContactPrinting System µCP2.1
Dimensions in total LxWxH= (42x40x35)cm³

7. µ-Contact Printing System µCP2.1
system housing

8. µ-Contact Printing System µCP2.1
photographs of the real device
c
b
General View on µCP2.1 a
• (a) inking station with 4 ink pads
• (b) drying nozzles, two per stamp
• (c) stamping unit

9. µ-Contact Printing System µCP2.1
a video-microscope is implemented from below
Stamping Unit
Slide Tray
Microscope
µCP2.1 mit Videomikroskop X-Y-Slide Tray and Stamp Head
(currently the chassis is under develeopment, the
visible one is a test approach only!)

10. µ-Contact Printing System µCP2.1
nano- and micro imprint on the same platform
µCP2.1 with an UV-light source
The commercial µCP2.1 will be equipped with a manually
driven slider, which holds video-microscope and UV-source.
As UV-light source we recommend a system from DELO
GmbH Germany, for example the system DELOLUX 80.

11. µ-Imprinting with the System µCP2.1
imprinting of thin polymer films
40µm
50µm
Fig.1: 1,0µm thick polymer film of an UV-active ink, Fig.2: 1,0µm thick polymer film of an UV-active ink,
coated on a standard glass slide, structure was coated on a standard glass slide like fig.1,
made by µ-imprinting using a PDMS-stamp, film lines width 20µm, pitch 40 µm
thickness 2µm, lateral dimensions of the squares
25x25µm², the connecting lines are 2µm wide (Ink
composition: 4-(2-[4-[2-[2-Cyanophenyl)-vinyl]-
phenyl]-vinyl)-benzonitril, diluted with
Tetrahydrofuran)

12. µ-Imprinting with the System µCP2.1
imprinting of spin coated photo restist films
Fig.3: Imprinted photo resist AZ-4562, 8µm thick, on Fig.4: Imprinted photo resist AZ-1514, 0.5µm
glass slide
PDMS-Stamp: height of structures10µm, lateral thick on glass slide
dimensions of the squares 25x25µm², the connecting PDMS-Stamp: like fig.3
lines are 2µm wide Method: like fig.3
Method: spin coating of a high viscous photo resist on a Remark: in picture 4 a status is shown, where
glass slide, imprinting the PDMS-stamp into the wet the imprinted resist is not back etched by RIE
resist, drying at RT without UV-radiation on air for 5min
Remark: in pictures 3 a status is shown, where the
imprinted resist is not back etched by RIE
scale bare: 50µm

13. µ-Contact Printing System µCP2.1
µm- scaled stamps made in PDMS
Fig.5: µ-Contact-Print on hydrophilic Fig.6: second contact print with the Fig. 7: third contact print with the same
glass slide using an PDMS-stamp inked same stamp and method of fig.5 stamp and method of fig.5 without
with a water based CY3-labeled buffer without nearly inking step nearly inking step
solution, stamp area 1x1cm², the
stamp pattern consists of thousands of
squares and connecting lines (see the
detail on the right), the stamp gets in
contact with the slide approx. 1 min
after the inking procedure 25x25µm²
Quadrate
Method: a) inking of PDMS-stamp for
1min, b) drying with compressed air 2
bar/30sec, c) stamp contact at 0,25bar
stamp-pressure/ 60sec. contact time
2µm Stege

14. µ-Contact Printing System µCP2.1
µ-Contact-Printing and parallel shifts of the substrate
Pattern: A=100
Ø A
A
Ø
2xA
A
A
2xA
Fig. 8: µ-Contact-Print on hydrophilic glass slide Fig.9: µ-Contact-Print on hydrophilic glass slide using an
using an PDMS-stamp inked with a water based PDMS-stamp inked with a water based CY3-labeled buffer
CY3-labeled buffer solution, stamp area 1x1cm²
Method: 2-STEP µ-Contact-Print with parallel shift of solution, stamp area 1x1cm²
600µm in the y-axis, Method: 2-STEP µ-Contact-Print with parallel shift of
PDMS-stamp: squares and circles are 100µm for 1200µm in the y-axis
parameter A (see detail drawing above) PDMS-stamp: squares and circles are 200µm for parameter
Remark: µCP2.1 allows a manually x-y-shift in A (see detail drawing above)
single steps of 500nm

15. µ-Contact Printing System µCP2.1
µ-Contact-Printing to transfer nano-particles
Fig.11: µ-Contact-Printing of spherical gold nano-
particles (Ø=37nm, diluted in water) on a
hydrophilic glass slide, PDMS-Stamp: no O2-
3µm 8µm plasma treatment stamp-design consists
of thousands of 8x8µm² mesa structures, which
are 10µm high (see the detail in fig.11), the
photograph was created by dark-field upright
microscopy, nano-particle clusters appears in
red
Method: a) inking of the PDMS-stamp, for 60sec
using 40µl of the nano-particle solution, b)
drying of the PDMS-stamp with compressed air
2,0 bar/30sec, c) contact printing, stamp
pressure 1,2 bar /contact time 60 sec

16. µ-Contact Printing System µCP2.1
µm- scaled stamps made in PDMS
25x25µm²
Quadrate
2µm Stege
Fig.12: µ-Contact-Printing of spherical gold nano-particles (Ø=37nm, diluted in water) on a hydrophilic silicon chip, PDMS-
stamp is not O2-plasma treated, stamp-design consists of thousands 25x25µm² mesa structures connected with 2µm
wide footbridges, the stamp pattern are 10µm high (see the detail in fig.12), the photograph was created by dark-field
upright microscopy, nano-particle clusters appears in a light green
Method: a) inking of the PDMS-stamp, for 60sec using 40µl of the nano-particle solution, b) drying of the PDMS-stamp with
compressed air 2,0 bar/30sec, c) contact printing, stamp pressure 1,2 bar /contact time 60 sec

17. µ-Contact Printing System µCP2.1
a first result
Fig.: The glass slide with poly-L-Lysin imprints made Fig.: The slide after a 19 hours cultivation of L929 cells.
with a PDMS-stamp. The stamp carries donut-mesa Each donut reacts as an adhesion point for the cells.
patterns wetted before with alginat.
Ref.: M. Gepp, H. Zimmermann - IBMT-St.Ingbert and S. Howitz - GeSiM, Großerkmannsdorf, June 2007

18. µ-Contact Printing System µCP2.1
example of a possible nano-structure Silicon-master
Approximated Master Price
4“- Silicon wafer with 10 master chips
containing indically patterns
6.500,- k€