Recently, microneedles (or microneedle arrays) for transdermal drug delivery have received increasing attention because they can provide painless, minimal invasiveness and time-released drug delivery. However, it is very difficult to design such an eligible microneedle that meets all the requirements for mechanical strength, small insertion force, and good biocompatibility. In this paper, we investigate a biomicroneedle: caterpillar spine. It is found that this type of biomicroneedle can pierce mouse skin using a very small force (about 173 μN) without fracture and buckling failures. Such excellent properties are mainly a result of its optimal geometry evolved by Nature, the high hardness, and the reasonable high elastic modulus near the tip end. This finding may provide an inspiration for the development of improved transdermal drug delivery microneedles.

References

References
1.
Arora
,
A.
,
Prausnitz
,
M. R.
, and
Mitragotri
,
S.
, 2008, “
Micro-Scale Devices for Transdermal Drug Delivery
,”
Int. J. Pharm.
,
364
, pp.
227
236
.
2.
Browen
,
L.
, and
Langer
,
R.
, 1988, “
Transdermal Delivery of Drugs
,”
Annu. Rev. Med.
,
39
, pp.
221
229
.
3.
Henry
,
S.
,
McAllister
,
D. V.
,
Allen
,
M. G.
, and
Prausnitz
,
M. R.
, 1998, “
Microfabricated Microneedles: A Novel Approach to Transdermal Drug Delivery
,”
J. Pharm. Sci.
,
87
, pp.
922
925
.
4.
Brazzle
,
J. D.
,
Mohanty
,
S.
, and
Frazier
,
A. B.
, 1999, “
Hollow Metallic Micromachined Needles With Multiple Output Ports
,”
Proc. SPIE Microfluidic Dev. Syst. II
,
3877
, pp.
257
266
.
5.
Davis
,
S. P.
,
Martanto
,
W.
,
Allen
,
M. G.
, and
Prausnitz
,
M. R.
, 2005, “
Hollow Metal Microneedles for Insulin Delivery to Diabetic Rats
,”
IEEE Trans. Biomed. Eng.
,
52
(
5
), pp.
909
915
.
6.
Park
,
J. H.
,
Allen
,
M. G.
, and
Prausnitz
,
M. R.
, 2005, “
Biodegradable Polymer Microneedles: Fabrication, Mechanics and Transdermal Drug Delivery
,”
J. Control. Release
,
104
, pp.
51
66
.
7.
Park
,
J. H.
,
Allen
,
M. G.
, and
Prausnitz
,
M. R.
, 2006, “
Polymer Microneedles for Controlled-Release Drug Delivery
,”
Pharm. Res.
,
23
(
5
), pp.
1008
1019
.
8.
Zhang
,
P.
,
Dalton
,
C.
, and
Jullien
,
G. A.
, 2009, “
Design and Fabrication of MEMS-Based Microneedle Arrays for Medical Applications
,”
Microsyst. Tech.
,
15
(
7
), pp.
1073
1082
.
9.
Lee
,
K.
,
Lee
,
H. C.
,
Lee
,
D. S.
, and
Jung
,
H.
, 2010, “
Drawing Lithography: Three-Dimensional Fabrication of an Ultrahigh-Aspect-Ratio Microneedle
,”
Adv. Mater.
,
22
(
4
), pp.
483
486
.
10.
Davis
,
S. P.
,
Landis
,
B. J.
,
Adams
,
Z. H.
,
Allen
,
M. G.
, and
Prausnitz
,
M. R.
, 2004, “
Insertion of Microneedles Into Skin: Measurement and Prediction of Insertion Force and Needle Fracture Force
,”
J. Biomech.
,
37
, pp.
1155
1163
.
11.
Roxhed
,
N.
,
Gasser
,
T. C.
, and
Griss
,
P.
, 2007, “
Penetration-Enhanced Ultrasharp Microneedles and Prediction on Skin Interaction for Efficient Transdermal Drug Delivery
,”
J. Microelectromech. Syst.
,
16
, pp.
1429
1440
.
12.
Khanna
,
P.
,
Luongo
,
K.
,
Strom
,
J. A.
, and
Bhansali
,
S.
, 2010, “
Sharpening of Hollow Silicon Microneedles to Reduce Skin Penetration Force
,”
J. Micromech. Microengin.
,
20
(
4
), p.
045011
.
13.
Du
,
B. Y.
,
Liu
,
J. P.
,
Zhang
,
Q. L.
, and
He
,
T. B.
, 2001, “
Experimental Measurement of Polyethylene Chain Modulus by Scanning Force Microscopy
,”
Polymer
,
42
, pp.
5901
5907
.
14.
Li
,
X. D.
,
Gao
,
H. S.
,
Murphy
,
C. J.
, and
Gou
,
L. F.
, 2004, “
Nanoindentation of Cu2O Nabicybes
,”
Nano Lett.
,
4
(
10
), pp.
1903
1907
.
15.
Li
,
X. D.
,
Gao
,
H. S.
,
Murphy
,
C. J.
, and
Caswell
,
K. K.
, 2003, “
Nanoindentation of Silver Nanowires
,”
Nano Lett.
,
3
(
11
), pp.
1495
1498
.
16.
Losic
,
D.
,
Short
,
K.
,
Mitchell
,
J. G.
,
Lal
,
R.
, and
Voelcker
,
N. H.
, 2007, “
AFM Nanoindentations of Diatom Biosilica Surfaces
,”
Langmuir
,
23
, pp.
5014
5201
.
17.
Oliver
,
W. C.
, and
Pharr
,
G. M.
, 1992, “
An Improved Technique for Determining Hardness and Elastic Modulus Using Load and Displacement Sensing Indentation Experiments
,”
J. Mater. Res.
,
7
(
1
), pp.
1564
1583
.
18.
Oliver
,
W. C.
, and
Pharr
,
G. M.
, 2004, “
Measurement of Hardness and Elastic Modulus by Instrumented Indentation: Advances in Understanding and Refinements to Methodology
,”
J. Mater. Res.
,
19
(
1
), pp.
3
20
.
19.
Timoshenko
,
S. P.
, and
Gere
,
J. M.
, 1972,
Mechanics of Materials
,
Van Nostrand Reinhold
,
New York
.
20.
Kong
,
X. Q.
, and
Wu
,
C. W.
, 2009, “
Measurements and Prediction of Insertion Force for the Mosquito Fascicle Penetration Into Human Skin
,”
J. Bionic. Eng.
,
6
, pp.
143
152
.
21.
Lu
,
T. J.
, and
Xu
,
F.
, 2008, “
Mechanical Properties of Skin: A Review
,”
Adv. Mech., (Chinese)
,
38
, pp.
393
426
.
22.
Duck
,
F.A.
, 1990,
Physical Properties of Tissue: A Comprehensive Reference Book
,
Academic Press
,
New York
.
23.
Hendriks
,
F. M.
, 2005, “
Mechanical Behavior of Human Epidermal and Dermal Layers in Vivo
,” Doctoral Thesis, Technische Universiteit, Eindhoven.
24.
Jacquemoud
,
C.
,
Bruyere-Garnier
,
K.
, and
Coret
,
M.
, 2007, “
Methodology to Determine Failure Characteristics of Planar Soft Tissues Using a Dynamic Tensile Test
,”
J. Biomech.
,
40
(
2
), pp.
498
475
.
25.
Johnson
,
K. L.
, 1985,
Contact Mechanics
,
Cambridge University Press
,
Cambridge
.
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