Acoustic Micro/Nano Manipulations: An Editorial Review
JunHui
Hu
JunHui Hu, Chang-Jiang Distinguished, Professor, State Key Lab of
Mechanics and Control of Mechanical Structures, Nanjing University of
Aeronautics and Astronautics, China
Correspondence to: JunHui Hu, Chang-Jiang Distinguished, Professor,
State Key Lab of Mechanics and Control of Mechanical Structures, Nanjing
University of Aeronautics and Astronautics, China.
Email: ejhhu@nuaa.edu.cn
Telephone: +86-25-84891681
Fax:
+86-25-84893075
Received: November 12,
2014
Revised: December 16, 2014
Accepted: December 19, 2014
Published online: December
31, 2014
ABSTRACT
Acoustic
micro/nano manipulation is a technology to handle or actuate micro/nano objects
in a controlled way by physical effects of sound waves. In this editorial
review, principles employed by acoustic micro/nano manipulations are listed and
briefly explained, and the manipulation functions based on these principles are
described. Also, the technological challenges in acoustic micro/nano
manipulations are pointed out.
© 2014 ACT. All
rights reserved.
Key words: Manipulation; Micro/Nano; Sound
Hu JH. Acoustic
Micro/Nano Manipulations: An Editorial Review. International
Journal of Radiology 2014; 1(1): 1-3 Available from: URL:
http://www.ghrnet.org/index.php/ijr/article/view/914
Editorial
With the development of fields such as biomedicine, micro/nano
fabrication, nanoscience and nanotechnology, material engineering, renewable
energy, etc., more actuation functions for micro/nano objects are being
required[1,2]. They include trapping (or capture), orientation,
transfer, release, sorting, revolution, spin, removal, concentration, assembly,
etc. These actuation tasks are also called manipulations. However, most of the
above listed manipulations cannot be effectively and efficiently realized by
the conventional actuation technology, which have limited driving forms and
operating principles[2].
To fulfill the
micro/nano manipulation functions, researchers in various academic areas have
proposed and investigated lots of strategies. These strategies can be
classified as optical[1,3], magnetic[4], electric[5],
mechanical[6], AFM[7], microfludic[8] and
acoustic methods[9-15], based on the physical principles which they
use.
The acoustic
micro/nano manipulation technology utilizes physical effects of sound to
manipulate micro/nanoscale solids, and micro/nanoliter droplets and bubbles. It
has the features such as no selectivity to material properties of manipulated
samples, little heat damage to manipulated samples (in some methods), diverse
manipulation functions, simple and compact device structures, etc. Operating
frequency in acoustic micro/nano manipulations may be in the ultrasonic range (>20
kHz) or several ten to several hundred Hz (in audible sound range).
Physical
effects of sound, employed by the acoustic micro/nano manipulation technology,
include the acoustic radiation force[2,16-19], acoustic streaming[19-21],
vibration based frictional driving[22], Chladni effect[23,24],
acoustic cavitation[25,26], Bjerknes forces[2,27-29], and
sound induced intermolecular force decrease[2,30-34]. So far, the
acoustic radiation force and acoustic streaming are two mostly utilized
physical effects in acoustic micro/nano manipulations.
The acoustic
radiation force is mainly used to manipulate micro objects. It may be generated
by the standing wave[2,5,9,19,35-37], focused beam[10]
and travelling wave[2,11,17]. The standing wave may be generated by
the radiation face-reflector structure[2] or SAW (surface acoustic
wave) device[19]. The acoustic radiation force generated by a
standing wave can push micro objects in the acoustic field to the sound
pressure nodes (or anti-nodes) and make them concentrating at the positions. It
is quite effective in concentrating multiple micro particles in a standing
wave. However, the standing wave method is not fit for the manipulations of
individual micro objects and relatively complicated manipulation functions such
as the controlled assembly of micro components. The focused beam method uses
the focal point of an ultrasonic beam to trap a single micro object or several
micro objects. The trapped micro object(s) can be transferred by simply moving
the ultrasonic transducer generating the ultrasonic beam. However, the
stability of the trapped micro object is poor owing to the noncontact working
principle, and strong ultrasound at the focal point may cause a high
temperature rise to damage the biological samples and other heat sensitive
samples. The travelling wave method utilizes large spatial gradient of sound
field near a radiation point, line or surface vibrating in-plane to generate
the acoustic radiation force to attract micro objects onto the radiation source.
It has the capability of trapping and rotating single or multiple micro
objects, and the stability of the trapped sample(s) is better. However, wet and
soft samples trapped by this method may stick to the manipulating probe, and
releasing the sample(s) from the manipulating probe in a controlled way is
still a big challenge[38,39]. Another technological challenge in the
travelling wave method is how to decrease the temperature rise in the
manipulation part.
The acoustic
streaming generates the manipulating force required by acoustic nano
manipulations. At the present stage, almost all of the acoustic nano
manipulations rely on the acoustic streaming[2]. It can be generated
by the spatial gradient of Reynolds stress and the 2nd order sound
pressure in a sound field, collapse of acoustic bubbles, or elliptical motion
of a micro manipulation probe. Realized functions of the acoustic nano
manipulations include trapping, orientation, positioning, transfer and rotation
of individual nanowires in deionized water, and concentration of nanowires and
nanoparticles in deionized water[2,15,40-42]. In the acoustic nano
manipulations, the temperature rise at the manipulation area is usually very
low, and can be lower than 0.1℃[15]. This feature
makes the acoustic nano manipulation technology very competitive in the
handling of biological and heat sensitive samples. In the acoustic nano
trapping, a trapped nano object may be in contact or not in contact with the
manipulation probe[2,15,40,42]. The acoustic nano concentration can
be implemented in a water droplet on an ultrasonic stage in vibration[2,43],
or in a water film excited by an acoustic needle suspended above stationary
substrate[2,44]. To enhance the devices’ manipulation performance, acoustic
streaming fields in the devices need to be quantitatively analyzed, and
vibration control methods of the ultrasonic transducers need to be explored.
Other physical
effects of sound such as the vibration based frictional driving, Chladni effect,
acoustic cavitation, Bjerknes forces, and sound induced intermolecular force
decrease also have applications in acoustic micro/nano manipulations. In the
vibration based frictional driving technique, the elliptical motion of solid
surface with a travelling wave is employed to drive micro objects on the
surface of a substrate. Methods of generating the travelling wave may be found
in Refs[22-24]. The
vibration based frictional driving of micro objects may be used in particle
transportation and separation[45,46], rotary driving of micro
mechanical components[23-24], etc. In the Chladni effect, the impact
between a vibration surface and particulate matters on the vibration surface is
used to drive the particulate matters to the vibration nodes of the vibration
surface. The Chladni effect provides a positioning force in the travelling wave
based rotary driving around vibration nodes of a plate in the flexural twisting
vibration mode[2,23-24]. The acoustic cavitation is a well known
physical effect of ultrasound, in which micro bubbles are generated in a sound
field in liquid[25-26]. Its recent applications include the pore
size increase of cells and the dispersion of micro/nano particulate matters in
solution[47]. The Bjerknes forces are a special acoustic radiation
force acting on vibrating bubbles in liquid[27-29]. This force is
useful in the concentration of micro particles in liquid. Acoustic vibration in
liquid can cause the decrease of intermolecular cohesive force such as Van Der
Walls force and Hydrogen bonding among liquid molecules[2,30-32,34],
no matter whether the acoustic cavitation has occurred or not. This effect has
been employed in the driving of micro fluid[30-33], merging of micro
droplets[34], etc. Compared with the acoustic radiation force and
acoustic streaming, physical effects such as the vibration based frictional
driving, Chladni effect, acoustic cavitation, Bjerknes forces, and sound
induced intermolecular force decrease still haven’t been explored sufficiently.
They are worthy of being investigated thoroughly in basic principle, device
design theory and applications, due to their potentials in micro/nano
manipulations.
Acoustic
micro/nano manipulation technology is an emerging academic field, generated by
the merging of Acoustics and actuation technology, to meet the diversified
requirements of handling micro/nano scale objects. Although it has very large
potential applications in the fields such as biomedicine, micro/nano
fabrication, nanoscience, material engineering, renewable energy, etc.,
researches on the principle, structure design, and application of the devices
are still superficial and insufficient. Constructive experiments and in-depth
theoretical analyses, which are key to achieve the breakthroughs, are needed
and will definitely push acoustic micro/nano manipulation technology
forward.
CONFLICT OF INTERESTS
There are no
conflicts of interest with regard to the present study.
REFERENCES
1
Ashkin A. Optical Trapping &
Manipulation of Neutral Particles Using Lasers. Singapore: World Scientific
Publishing, Dec. 2006.
2
Hu J. Ultrasonic Micro/Nano
Manipulations, Singapore: World Scientific Publishing, April 2014.
3
Ashkin A ,
Acceleration and trapping of particles by radiation pressure, Phys. Rev. Lett.,
vol. 24, pp. 156-159, 1970.
4
Tanase M, Bauer LA, Hultgren A,
Silevitch DM, Sun L, Reich DH, Searson PC, Meyer GJ. Magnetic alignment of
fluorescent nanowire, Nano Lett., vol.1 (3), pp. 155-158, 2001.
5
Castillo J, Dimaki M, Svendson WE,
Manipulation of biological samples using micro and nano techniques, Integr.
Biol., 1, pp. 30-42, 2009.
6
K. Molhave, T. Wich, A. Kortschack, and
P. Boggild, Pick–and–place nanomanipulation using microfabricated grippers,
Nature Nanotech., vol. 17 (10), pp. 2434, 2006.
7
M. Sitti, B. Aruk, K. Shintani, and H.
Hashimoto, Scaled teleoperation system for nano–scale interaction and
manipulation, Advanced Robotic, vol. 17 (3), pp. 275-291, 2003.
8
J. Pihl, J. Sinclair, M. Karlsson, and
O. Orwar, Microfluidics for cell–based assays, Mater. Today, 8 (12), pp. 46-51,
2005.
9
W. T. Coakley, D. W. Bardsley, and M. A.
Grundly, Cell manipulationin ultrasonic standing wave fields, J. Chem. Technol.
Biotechnol., vol. 44 (1), pp. 43-62, 1989.
10 J.
Wu, Acoustic tweezers, J. Acoust. Soc. Am., vol. 89 (5), pp. 2140-2143, 1991.
11 J.
Hu, J. Yang, and J. Xu, Ultrasonic trapping of small particles by sharp edges
vibrating in a flexural mode, Appl. Phys. Lett., vol. 85 (24), pp. 6042-6044,
2004.
12 J.
Hu, C. Tay, Y. Cai, and J. Du, Controlled rotation of
sound–trapped small particles by an acoustic needle, Appl. Phys. Lett., vol. 87
(9), 094104, 2005.
13 R. D.
O’Rorke, C. D. Wood, C. Walti, S. D. Evans, and A. G. Davies, Acousto-microfluidics:
Transporting microbubble and microparticle arrays in acoustic traps using
surface acoustic waves, J. Appl. Phys., vol.111 (9), 094911, 2012.
14 A. P.
Sarvazyan, O. V. Rudenko,W. L. Nyborg, Biomedical
applications of radiation force of ultrasound: historical roots and physical
basis, Ultrasound Med. Biol., vol. 36(9), 1379-1394, 2010.
15 N.
Li, J. Hu, H. Li, S. Bhuyan, and Y. Zhou, Mobile acoustic streaming based
trapping and 3–dimensional transfer of a single nanowire, Appl. Phys. Lett.,
vol.101 (9), pp. 093113, 2010.
16 T.
Hasegawa, T. Kido, T. Iizuka, and C. Matsuoka, A general theory of Rayleigh and
Langevin radiation pressures, J. Acoust. Soc. Jpn. (E), vol. 21 (3), pp.
145-152, 2000.
17 Y.
Liu, J. Hu, and C. Zhao, Dependence of acoustic trapping capability on the
orientation and shape of particles, IEEE Trans. Ultrason. Ferroelectr. Freq.
Control, vol. 57 (6), pp. 1443–1450, 2010.
18 L. P.
Gor’kov, On the forces on a small particle in an
acoustical field in an ideal fluid, Sov. Phys.–Dokl., vol. 6 (9), pp. 773-775,
1962.
19 J.
Friend, and L. Y. Yeo, Microscale acoustofluidics: microfluidics driven via
acoustics and ultrasonics, Rev. Mod. Phys., vol. 83, pp. 647-704, 2011.
20 W. L.
Nyborg, Physical Acoustics (edited by W. P. Mason and R. N. Thurston). New York : Academic Press, pp. 267-303, 1966.
21 J.
Lighthill, Acoustic streaming, J. Sound Vib., vol. 61,
pp. 391-418, 1978.
22 S.
Ueha, and Y. Tomikawa, Ultrasonic Motors: Theory and Applications, Oxford:
Oxford University Press, pp. 32, 1994.
23 Y. Zhou,
H. Li, and J. Hu, An ultrasonic stage for controlled spin of micro articles,
Rev. Sci. Instrum., vol. 83, 045004, 2012.
24 X.
Zhu, and J. Hu, Ultrasonic drive of small mechanical components on a tapered
metal strip, Ultrasonics, vol. 53, pp. 417-422, 2013.
25 F. R.
Young, Cavitation, London: Imperial College Press, pp. 6 & 160, 1999.
26 T. J.
Mason, and J. P. Lorimer, Applied Sonochemistry: Use of Power Ultrasound in
Chemistry and Processing, Germany:Wiley–VCH Verlag
GmbH & Co. KGaA, Weiheim, pp. 40 & 45, 2002.
27 T. G.
Leighton, A. J. Walton, and M. J. Pickworth, Primary bjerknes forces, Eur. J.
Phys., vol. 11, pp. 47-50, 1990.
28 L. A.
Crum, Bjerknes forces on bubbles in a stationary sound field, J. Acoust. Soc.
Am., vol. 57, pp. 1363-1370, 1975.
29 R.
Mettin, I. Akhatov, U. Parlitz, C. D. Ohl, and W. Lauterborn, Bjerknes forces
between small cavitation bubbles in a strong acoustic field, Phys. Rev. E:
Stat. Phys., Plasmas, Fluids, vol. 56, pp. 2924-2931, 1997.
30 J.
Hu, C. Tan, and W. Hu, Ultrasonic microfluidic transportation based on a
twisted bundle of thin metal wires, Sens. Actuators, A: Physical, vol. 135, pp.
811-817, 2007.
31 Z.
Tan, G. Teo, Ultrasonic generation and rotation of a small droplet at the tip
of a hypodermic needle, J. Appl. Phys., vol. 104, 104902, 2008.
32 J.
Hu, N. Li, and J. Zhou, Controlled adsorption of droplets onto anti–nodes of an
ultrasonically vibrating needle, J. Appl. Phys., vol. 110, 054901, 2011.
33 C.
Yun, T. Hasegawa, K. Nakamura, and S. Ueha, An ultrasonic suction pump with no
physically moving parts, Jpn. J. Appl. Phys., vol. 43, pp. 2854-2868, 2004.
34 S.
Bhuyan, Wireless drive of Piezoelectric Components, PhD thesis, Nanyang
Technological University, Singapore, Chapter 7, pp. 147, 2010.
35 J. H.
Hu, and A. K. Santoso, A Pi–shaped ultrasonic tweezers concept for manipulation
of small particles, IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 51 (11),
pp. 1499-1507, 2004.
36 D.
Bazou, L. Kuznetsova, and W. T. Coakley, Physical enviroment of 2–D animal cell
aggregates formed in a short pathlength ultrasound standing wave trap,
Ultrasound Med. Biol., vol.31 (3), pp. 423-430, 2005.
37 A. L.
Bernassau, C. R. P. Courtney, J. Beeley, B. W. Drinkwater, and D. R. S.
Cumming, Interactive manipulation of microparticles in an octagonal
sonotweezer, Appl. Phys. Lett., vol. 102, 164101, 2013.
38 Y.
Toku, K. Kobayashi, M. Muraoka, Repositioning technique in nanowire
manipulation by oscillating gripper, Micro Nano Lett, vol. 8(2), pp. 63-65,
2013.
39 S.
Guo, Y. Wang, N. Allbritton, X. Jiang, Ultrasound-induced release of
micropallets with cells”, Appl. Phys. Lett., vol. 101, 163703, 2012.
40 H.
Li, J. Hu, Noncontact manipulations of a single nanowire using an ultrasonic
micro-beak, IEEE T Nanotechnol., vol. 13(3), 469-474, May 2014.
41 N.
Li, J. Hu, Sound controlled rotary driving of a single nanowire, IEEE T
Nanotechnol., 13(3), 437-441, May 2014.
42 A. L.
Balk, L. O. Mair, P. P. Mathai, P. N. Patrone, W. Wang, S. Ahmed, T. E. Mallouk,
J. A. Liddle, and S. M. Stavis, Kilohertz rotation of nanorods propelled by
ultrasound, traced by microvortex advection of nanoparticles, ACS Nano, vol.
8(8), pp. 8300-8309, 2014.
43 Y.
Zhou, J. Hu, S. Bhuyan, Manipulations of silver nanowires in a droplet on
low-frequency ultrasonic stage, IEEE Trans. Ultrason. Ferroelectr. Freq.
Control, vol. 60(3), pp.622-629, 2013.
44 B.
Yang and J. Hu, Linear Concentration of microscale samples under an
ultrasonically vibrating needle in water on a substrate surface, Sensor.
Actuat. B, vol. 193, pp. 472-477, 2014.
45 M.
Mracek, J. Wallascheck, A system for powder transportation based on
piezoelectrically excited ultrasonic progressive waves (Review), Mater Chem
Phys, vol. 90, pp. 378-380, 2005.
46 H.
Ba, J. Hu, Separation of small solid particles based on ultrasonic rotary, Sep
Purif Technol, vol. 127, pp. 107-111, 2014.
47 P.
Marmottant, S. Hilgenfeldt, Controlled vesicle deformation and lysis by single
oscillating bubbles, Nature, vol. 422(6936), pp.153–156, May 2003.
Peer reviewer: Puneet Mittal,
Department of Radiodiagnosis, MMIMSR, Mullana, Ambala, Haryana, 133207, India.
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