Piezo drop-on-demand inkjet printers are used in an increasing number of applications because of their reliable deposition of droplets onto a substrate. Droplets of a few picoliters are ejected from an inkjet nozzle at frequencies of up to 100 kHz. However, the entrapment of an air microbubble in the ink channel can severely impede the productivity and reliability of the printing system. The air bubble disturbs the channel acoustics, resulting in disrupted drop formation or failure of the jetting process. Here we study a micro-electro-mechanical systems-based printhead. By using the actuating piezo transducer in receive mode, the acoustical field inside the channel was monitored, clearly identifying the presence of an air microbubble inside the channel during failure of the jetting process. The infrared visualization technique allowed for the accurate sizing of the bubble, including its dynamics, inside the intact printhead. A model was developed to calculate the mutual interaction between the channel acoustics and the bubble dynamics. The model was validated by simultaneous acoustical and infrared detection of the bubble. The model can predict the presence and size of entrapped air bubbles inside an operating ink channel purely from the acoustic response.

1.
M.
Singh
,
H. M.
Haverinen
,
P.
Dhagat
, and
G. E.
Jabbour
,
Adv. Mater.
22
(
6
),
673
(
2010
).
2.
H.
Wijshoff
,
Phys. Rep.
491
(
4–5
),
77
(
2010
).
3.
E.
Peeters
,
IEEE Comput. Sci. Eng.
4
(
1
),
44
(
1997
).
4.
C.
Menzel
,
A.
Bibl
, and
P.
Hoisington
, “
MEMS Solutions for Precision Micro-Fluidic Dispensing Application
,” technical report, FUJIFILM Dimatix, Inc.,
2004
.
5.
J.
de Jong
,
G.
de Bruin
,
H.
Reinten
,
M.
van den Berg
,
H.
Wijshoff
,
M.
Versluis
, and
D.
Lohse
,
J. Acoust. Soc. Am.
120
(
3
),
1257
(
2006
).
6.
C. E.
Brennen
,
Cavitation and Bubble Dynamics
(
Oxford University Press
,
New York
,
1995
).
7.
T. G.
Leighton
,
The Acoustic Bubble
(
Academic
,
London
,
1994
).
8.
S.
Hilgenfeldt
,
D.
Lohse
, and
M.
Zomack
,
Eur. Phys. J. B
4
(
2
),
247
(
1998
).
9.
M. P.
Brenner
,
S.
Hilgenfeldt
, and
D.
Lohse
,
Rev. Mod. Phys.
74
(
2
),
425
(
2002
).
10.
V.
Garbin
,
B.
Dollet
,
M.
Overvelde
,
D.
Cojoc
,
E.
Di Fabrizio
,
L.
van Wijngaarden
,
A.
Prosperetti
,
N.
de Jong
,
D.
Lohse
, and
M.
Versluis
.
Phys. Fluids
21
(
9
),
092003
(
2009
).
11.
J.
de Jong
,
R.
Jeurissen
,
H.
Borel
,
M.
van den Berg
,
H.
Wijshoff
,
H.
Reinten
,
M.
Versluis
,
A.
Prosperetti
, and
D.
Lohse
,
Phys. Fluids
18
(
12
),
121511
(
2006
).
12.
J.
Chung
,
C. P.
Grigoropoulos
, and
R.
Greif
J. Microelectromech. Syst.
12
(
3
),
365
(
2003
).
13.
G.
Han
,
J. C.
Bird
,
K.
Johan
,
A.
Westin
,
C.
Zhiqiang
, and
K. S.
Breuer
,
Microscale Thermophys. Eng.
8
(
2
),
169
(
2004
).
14.
D.
Liu
,
S. V.
Garimella
, and
S. T.
Wereley
,
Exp. Fluids
38
(
3
),
385
(
2005
).
15.
R.
Jeurissen
,
J.
de Jong
,
H.
Reinten
,
M.
van den Berg
,
H.
Wijshoff
,
M.
Versluis
, and
D.
Lohse
,
J. Acoust. Soc. Am.
123
(
5
),
2496
(
2008
).
16.
R.
Jeurissen
,
A.
van der Bos
,
H.
Reinten
,
M.
van den Berg
,
H.
Wijshoff
,
J.
de Jong
,
M.
Versluis
, and
D.
Lohse
,
J. Acoust. Soc. Am.
126
(
5
),
2184
(
2009
).
17.
E.
Bassous
,
H. H.
Taub
, and
L.
Kuhn
,
Appl. Phys. Lett.
31
(
2
),
135
(
1977
).
18.
Océ Technologies B.V., for more information on Océ CrystalPoint technology see http://global.oce.com/technologies/crystalpoint-technology. aspx.
19.
E.
Hecht
,
Optics
, 4th ed. (
Pearson Education
,
New York
,
2001
).
20.
K. S.
Kwon
and
W.
Kim
,
Sens. Actuators, A
140
,
75
(
2007
).
21.
K. S.
Kwon
,
Sens. Actuators, A
153
(
1
),
50
(
2009
).
22.
ANSYS CFD, For more information about ANSYS CFD see http://www.ansys.com/.
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