Robot-aided electrospinning toward intelligent biomedical engineering
Tan et al. Robot. Biomim.
Robot-aided electrospinning toward intelligent biomedical engineering
Rong Tan 0
Xiong Yang 0
Yajing Shen 0
0 City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, SAR
The rapid development of robotics offers new opportunities for the traditional biofabrication in higher accuracy and controllability, which provides great potentials for the intelligent biomedical engineering. This paper reviews the state of the art of robotics in a widely used biomaterial fabrication process, i.e., electrospinning, including its working principle, main applications, challenges, and prospects. First, the principle and technique of electrospinning are introduced by categorizing it to melt electrospinning, solution electrospinning, and near-field electrospinning. Then, the applications of electrospinning in biomedical engineering are introduced briefly from the aspects of drug delivery, tissue engineering, and wound dressing. After that, we conclude the existing problems in traditional electrospinning such as low production, rough nanofibers, and uncontrolled morphology, and then discuss how those problems are addressed by robotics via four case studies. Lastly, the challenges and outlooks of robotics in electrospinning are discussed and prospected.
Robotics; Electrospinning; Biomedical engineering
The basic idea of electrospinning originated in the period
from 1934 to 1944, when researchers describes the use of
electrostatic force to produce polymer filament device.
The main principle is using high-voltage electrostatic
field to stimulate the polymer charged jet and then to
obtain the polymer nanofibers by charged jet curing.
From the middle of the twentieth century to present,
electrospinning technology ended up more than 60 years
of silence, and finally in the last decade of twentieth
century ushered in its glorious era. In 1994, “electrospinning”
became a professional term, instead of “electrostatic
spinning,” officially declared electrospinning as an
independent academic field, began its research and development
in the field of nanotechnology and related
bioengineering. At present, electrospinning is rapidly emerging as
a unique and versatile technique for the preparation of
smooth nanofibers with controllable morphology from
various polymers [
]. The nanofibers produced by
electrospinning have high surface area and highly porous
structure, and furthermore, design flexibility is an
important advantage of electrospun nanofibers .
Electrospinning has widely been used in
biomedical engineering, including wound dressings, filtration,
and drug delivery systems, as well as tissue engineering
]. Electrospinning process depends on
several parameters, including [
] the properties of solution
(viscosity, elasticity, electrical conductivity, and surface
tension), applied voltage, nozzle–collector distance,
ejection speed, surrounding temperature, humidity, air flow
rate, etc. Therefore, the precise control of each
parameter directly affects the morphology of the nanofibers [
In vivo, tissue engineering scaffolds must be not only a
three-dimensional structure which is required to mimic
extracellular matrix but also a high porosity, large surface
area, suitable pore size, and highly interconnected pore
]. Therefore, it is challenging for the
traditional electrospinning method to obtain such
biocompatibility, biodegradability, non-toxicity, and structural
integrity scaffolds precisely due to the randomly
intertwined nanofibers [
]. Hence, the urgent requirement
on electrospinning is how to precisely control the
morphology and diameter of electrospinning so that it can
produce thinner nanofibers with the structure of
threedimensional in biomedical engineering.
As an emerging technology, robotics has involved in
and benefits many biofabrication process to ensure and
improve the accuracy, flexibility, and controllability, such
as 3D printing, 3D plotting, nanoimprinting.
Robotaided electrospinning is integrating robot to general
electrospinning process to improve the control of
parameters, the diameter of nanofibers, the rate of producing
nanofibers, and so on. In this review, we summarize the
state of the art of electrospinning in biomedical
engineering and discuss how the robotics benefit the
electrospinning process, i.e., including its working principle, main
applications, challenges, and prospects.
Basic principle and technique of electrospinning
As the one of the most straightforward and cost-effective
method, electrospinning technique with unique
physiochemical property has gained an extensive application in
biomedical field [
]. An integrated electrospinning
device consists of a DC high-voltage supply, a syringe is
filled with polymer solution, a needle, and a collector. To
fabricate nanofibers, one electrode of DC high-voltage
supply is connected to the needle of the syringe, and the
polymer is ejected to the target collector from the top of
the needle. During the process, the polymer droplets are
held by the surface tension at the needle, which collects
the charge on the surface induced by the electric field,
while it receives an electric field force which is
opposite to the surface tension [
]. The droplets are pulled
from spherical to cone-shaped structure named
Taylorcone. However, the electric field force will overcome the
surface tension of the liquid when it increases to a critical
]. The polymer jet occurs under the influence of
high electric field, resulting in extremely high-frequency
irregular spiral motion [
]. Ultimately, a fiber of
nanometer diameter is formed and scattered on the collector in
a random manner to form a non-woven fabric [
Melt electrospinning and solution electrospinning
The solution electrospinning is a method for the
preparation of nanofibers by solvent evaporation and polymer
curing under the action of high-voltage electric field, and
the melt solution refers to the polymer heating and
melting, by the electric field force to be drawn to obtain
polymer fiber material process [
]. Structurally, both of them
have a nearly identical composition, except that the melt
electrospinning has an extra heater and that the
solution electrospinning has an infusion pump (Fig. 1a, b). In
addition, the low cost makes them a common advantage,
but these two methods differentiate themselves by their
Solution electrospinning is well known for its
simplicity of operation and suitability for many polymers. The jet
of solution electrospinning has the virtue of low viscosity
and is easy to obtain nanofibers with diameter less than
100 nm. Besides, the surface of fiber presents the porous
structure due to solvent evaporation [
]. The advantage
of melt electrospinning is that there is no need to find
the solvent for dissolving polymer, and the end-product
is suitable for the application of biomedical engineering
such as tissue engineering and drug release. In a sense, it
is easy to realize the mass production due to not require
the use of volatile solvents [
]. While comparing
these two approaches, solution electrospinning is facing
the challenges of significant solvent evaporation,
difficult direct-writing, and low output. In these and several
respects, as a kind of raw materials with wide
applicability, favorable direct-writing capability, non-toxic
pollution, and high conversion rate of product technology,
the melt electrospinning handles better than the solution
electrospinning, but it requires severe external conditions
like higher spinning temperature, more time to build, and
heat-resistant polymers .
Nevertheless, these two techniques are difficult to
achieve the requirement of high-precision pattern and
structure when the polymer steps into the instability
motion and splitting process [
] since the high
voltage (≤ 10 kV) limits softness of nanofibers and choice of
polymer materials. Finally, this could lead to create
randomly coiled fibers and form uncontrolled construction.
The next, the solution of spinning issues caused by the
high voltage is presented.
Near-field electrospinning is a technology for
depositing solid nanofibers in a direct, continuous, and
controllable manner by reducing the spinning distance to
decrease the voltage [
]. The process is done by
replacing a common needle with a tungsten needle and
dipping some polymer to from droplet for spinning [
]. In order to accurately control and straightly write
the physical properties and precisely present 2D and 3D
structure, near-field electrospinning as though jumped
out in front of researchers [
]. It becomes one of the
most potentially technique in all sorts of fields like tissue
engineering, drug delivery, biomedical engineering [
Compared with melt electrospinning and solution
electrospinning, near-field electrospinning is a similar
assembly device including high-voltage supply, probe tip, and
collector (Fig. 1c), but it can achieve low-voltage
electrospinning (≤ 0.2 kV) by changing conditions,
directwriting orderly and patterned nanofibers and preventing
it from fabricated chaotic nanofibers [
comparing process, the comparison of details (Table 1) is shown
by He et al. . Among of all changing condition’s
methods for reducing voltage, dropping off the spinning
distance is regarded as the most effective way, and then
adding additional conditions (e.g., magnetic field force)
to decrease the electric filed also was reported by Yang
et al. [
Although near-field electrospinning is termed a best
tool to deposit solid nanofibers in using direct-write, it
is not capable enough to fabricate mass production with
its single nozzle; moreover, it is easy to cause fiber
diameters become thicker because of shortening
spinneret-tosubstrate distance [
]. Facing this a series of questions,
researchers are using robot-aided for realizing large-scale
production of electrospinning, and thinner nanofibers
will be applied in much more fields.
Applications of electrospinning in biomedical engineering
The main function of electrospinning technology is to
prepare polymer nanofibers, which can be then designed
to biomedical material, nanosensor, and nanofiber
templates. As the nanofiber mats prepared by
electrospinning has the characteristics of high surface-to-volume
ratio, high porosity, and relatively uniform fiber diameter,
it has a unique property in its application. Also, the
electrospinning mats has a favorable bionic property
including high biocompatibility. Then, this thesis illustrates the
application in three fields.
Applications for drug delivery
Drug delivery systems (DDS) gained much attention
in recent years, as drug-loaded materials and
nanofibers mats prepared by electrospinning have many
advantages, such as controlled release of drugs, little influence
on the activity of drugs, and good biocompatibility.
Kenawy et al. introduced that the release rates from the
polyurethane, polyurethane, and their blend are similar.
However, mixture of these two materials improved its
visual mechanical properties [
]. Therefore, further
confirmed nanofiber mats provide a scaffold with suitable
mechanical strength for drug release. In terms of drug
release, Zamani et al. [
] and Jing et al. [
proposed some examples to achieve slow release of
metronidazole by progressive degradation of PCL and using
degradable PLLA as support material respectively. In
addition, the core–shell structure nanofibers and
multilayered drug-loaded biodegradable nanofiber can be used
as a carrier material to avoid the burst release of drugs.
Sun et al. [
] developed that core–shell nanofibers could
be produced by co-electrospinning or coaxial
electrospinning two different polymer solutions, such as
polysulfone (PSU) and poly (ethylene oxide) (PEO), as well as
PEO–PEO, through a spinneret comprising two coaxial
capillaries (Fig. 2). On this basis, Jiang et al. [
prepared the core–shell nanofibers by using coaxial spinning
method, and controlled release of biological reagents
(bovine serum and lysozyme) was realized.
On this aspect of using multilayered drug-loaded
biodegradable nanofiber, Tatsuya et al. [
] developed the
use of multilayered drug-loaded biodegradable nanofiber
as a drug carrier material, by controlling the diameter of
the fiber and the thickness of non-drug layer to achieve
the purpose of controlled release. Meanwhile, making use
of nanofibers prepared with the corresponding material
as a drug carrier material can also achieve this aim.
Although a wide variety of drugs for the treatment of
diseases have been successfully encapsulated into these
nanofibers, significant progress has been made in the
use of electrospun fibers for drug delivery, and many
problems remain to be resolved. First, in order to
produce uniform nanofibers with favorable
morphological, mechanical and chemical properties for realizing
its repeated and massive production are the challenge.
Second, how to make drug-loading content properly and
Fig. 2 Structure of co-electrospinning or coaxial electrospinning two
different polymer solutions for producing core–shell nanofibers [
efficiently and removal of residual organic solvent are
particularly important [
]. Third, we need to know that
nanofibers may cause an immune response or toxicity
when applying these nanofibers in vivo.
Applications for tissue engineering
Tissue engineering is an emerging discipline based on
the theory of biology that utilized innovations of biology,
medicine, and technology for restoring and maintaining
the functions of tissues and organs [
]. The research of
biomaterials plays an important role in tissue engineering
by acting as substrates for the cells growth, proliferation,
and new tissue formation in three dimensions [
this case, the electrospinning is an low-budget, versatile,
and powerful tool to produce nano- and ultrathin fibers
as mimetic scaffolds to the extracellular matrix
]. Scaffolds with special physical characteristics
like high surface-to-volume ratio are fabricated by
electrospinning technique for soft tissue engineering
applications in biomaterials field [
], and these invention is
regarded as the most conspicuous focus. Another reason
for becoming the spotlight is that it has the capability to
mimic the architecture of natural human extracellular
], and it affects cell binding and
spreading. C.T. Laurencin suggested that cells can attach and
organize properly around fibers with diameters smaller
than the corresponding cells [
]. Molly M. Stevens and
Julian H. George reported the scaffolds with nanoscale
architectures have bigger surface area for absorbing
proteins by comparing type of three scaffolds (Fig. 3) [
and the proteins further can provide an edge over
microscale architectures for tissue generation applications [
Therefore, cells can attach and organize properly around
fibers in scaffolds with nanoscale architectures.
For these reasons, nanofibrous scaffolds with its unique
advantages in suitable porosity, nanoscale
topography, and interconnectivity, it attracts more and more
researchers constantly. About this study of nanofibrous
scaffolds that better recapitulate tissue properties and
enhance regeneration [
], numerous research works
have been done and a lot of optimum design methods
were presented. A variety of polymeric nanofibers have
been considered for use as scaffolds for engineering
tissues like skin tissue engineering [
], bones [
], heart [
], etc. In 2011, Szentivanyi
et al. developed a cost-efficient and versatile approach to
generate three-dimensional scaffolds of different shape
and size [
]. Basu et al. succeed in researching and
producing PEO and CMC/PEO nanofibrous scaffolds with
3D porous network using electrospinning technique. In
addition, it is shown experimentally that nanofibrous
scaffolds have thermally stable characters and the
appreciable tensile properties for cell adherence and growth.
Fig. 3 Three types of scaffold and the condition of cell binding in each scaffold. a Micropore scaffold. b Microfiber scaffold. c Nanofiber Scaffold
MTT experimental results show that nanofibrous
scaffolds possess the property of non-toxicity and cell
However, there are several challenges that need to be
solved prior to use of electrospun grafts in clinical
applications. On the aspects of improving nanofibrous
scaffolds, we should consider some important parameters
such as fiber formation, morphology, composition, as
well as homogenous cell distributions. Accurate bionic
scaffold is the goal that researchers have been hoping to
Besides, the lack of cellular infiltration continues to
be the key of research with new techniques developed
to solve this challenge including dropping fiber packing
density, multilayered electrospinning, dynamic cell
culture, and cell electrospraying [
Applications for wound dressing
The electrospun non-woven mat was fabricated by
electrospinning which is a unique and versatile technique. It
possesses lots of advantages such as high air permeability,
high liquid absorption rate, and the flexible fitness to the
wound site [
]. In addition, electrospun non-woven
was regarded as material to be used in
wounding-healing process , because it can keep the wounds dry
and prevent them from infection [
]. Melaiye et al. [
developed electrospun nanofibers as carrier and
loadedsilver imidazole ring composite, and their anti-bacterial
action was studied for wound-healing materials. Hong
and Kyung Hwa reported a PVA/Ag composite nanofiber
mats as wound repair materials, due to the bactericidal
effect of Ag nanoparticles, and it is possible to prevent
wound infection and promote wound healing [
et al. introduced the non-woven wound dressing with
core–shell structured fibers, which was prepared by
coaxial electrospinning and then taking silver
nanoparticles (Ag-NPs) into the shell, whereas the vitamin A
palmitate (VA), healing-promoting drug, was encapsulated
in the core.
Furthermore, the dressing’s anti-bacterial ability
against Staphylococcus aureus was proved by in vitro
anti-bacterial test. The result shows (Fig. 4)
Staphylococcus was not inhibited in the medium without
loading with Ag–NPs and VA (Fig. 4a). By contrast, (Fig. 4b)
shows a significant inhibitory effect with the disappeared
bacteria line. This illustrates that this non-woven wound
dressing has the capacity to be used as clinical
woundhealing dressing [
However, the need of this non-woven wound
dressing for all trauma is not ideal because the skin wound is
heterogeneous between the patient groups, and thus the
skin regeneration should turn to personalized treatment
]. In addition, the possibility of its residual solvent is
so high, and it is difficult to produce a uniform nanofiber.
But it is easy to overcome by adjusting the parameters
As mentioned above, traditional electrospinning has its
merits as well as its limitations and demerits. Firstly, it is
difficult for the traditional electrospinning to accurately
control the direction of electrospinning and get the
specific three-dimensional structure in experiment. Secondly,
it is difficult to apply the nanofiber mats in medical
engineering directly due to the roughness of the produced
nanofiber surface. Beyond that, it also difficult to achieve
high productivity due to the individual nozzle. In order
to realize the position-controlled deposition and precise
integration of individual or aligned fibers with flexible
and functional devices [
], robotics attracted the
interest of researchers and attention of the electrospinning
field. Robotics provides better ability to move the needle
flexibly on the x–y–z axis because of direct computer
system control. Under the control of the processing, the
precise three-dimensional structure presented in front of the
researchers. In addition, robotics induces the change of
each parameter in the spinning process from the computer
system and further controls the process of electrospinning
for keeping the morphology and diameter of nanofibers.
Robot‑aided multi‑nozzle electrospinning
To improve the efficiency for mass production,
researchers proposed robotics multi-nozzle electrospinning
technique, which makes it possible to increase the
productivity and covering area [
]. In this process, the
accuracy is highly affected by the repulsion from the adjacent
jets and the non-uniform electric field on Taylorcone of
every needle. Around these problems, a number of
robotaided multi-nozzle NFEC apparatus were presented.
Many researchers hope to utilize increase the number
of nozzle to achieve the robot-aided control of uniform
In order to realize a robot-aided uniform electric field
strength, Yang et al. [
] utilized the design of an
equilateral triangle with each set of three needles and used
a shield ring to increase equilateral hexagon distributed.
Based on this, Fig. 5a, b shows the basic theory and the
specific construction method of Yang’s design,
summarizing the feasibility of bringing a shield ring to form
robot-aided uniform electric field and subsequently
uniform fibers at a high production rate from two
dimensions and three dimensions (Fig. 5c, d).
In 2015, Wang et al. [
] developed a robot-aided
multi-nozzle NFEC (with double-nozzle NFES and
triple-nozzle NFES) for reflecting the effect of the
nonuniform electric field generated at the nozzle tip (Fig. 6a).
These structures is made of high-voltage supply, syringe,
X-motion platform, chromium-plated glass and
camcorder, the X-motion platform, and chromium-plated
glass form the collector, and syringe consists of syringe
pump and spinneret array; the high-voltage supply was
connected to the spinneret array, which provided a
During the process, a camcorder was used to observe the
morphological variation of NFES jets which showed from
single nozzle to triple nozzle (Fig. 6b–d). It should be clear
that the jets could not keep the vertical line in process of
between double-nozzle NFES and triple-nozzle NFES,
respectively. Experimental results show the mutual
distance of deposition was mainly affected by nozzle spacing
and working distance rather than the voltage, and
furthermore the Coulomb force is one of the major causes of
interference for these phenomena, and it will lay the foundation
for the further study. Meanwhile, Kim et al. [
1-m cylinder-type high-speed robot-aided multi-nozzle
setup which have 120 Ea multi-nozzles installed into
cylinder block module (Fig. 7) to overcome above-mentioned
problems for realizing the large-scale production and
commercial operation. As a further mass production technique,
researchers saw possibilities in it. However, by
increasing the number of nozzle sense, a series of
technological advances were not large enough to give a suitable field
distribution for fabricating thinner or three-dimensional
nanofibers. Therefore, researchers need to develop a
robotically controlled movable multi-nozzle setup.
A robot‑assisted angled multi‑nozzle electrospinning
During the process of electrospinning, different
parameters have been reported to change the physicochemical
properties of fibers [
]. As the core of estimation,
parameters affect the uniform and morphology of fibers
]. Hence, to obtain uniform and hybrid material
fibers by comparing different parameters, Park et al. [
developed a multi-nozzle electrospinning setup with
tunable angle between the tips of the nozzles (Fig. 8). It was
composed of a removable and easy-to-control automated
robot system controlled by the LabVIEW 9.0 program,
two separate high-voltage power supplies created a
connection to the two metal capillary nozzles, respectively,
a cylindrical collector with Teflon sheet, two 10-ml
plastic syringes, and two syringe pumps [
moveable nozzle can be easily controlled via a fully automated
robot-aided system, and Fig. 6a shows the morphology
and diameter of different electrospun mats when
changing the angle of configurations (90°, 100°, and 180°) with
nozzle holder held in the fixed position. The diameter of
fibers increases with the number of angle configurations.
By contrast, the diameter reduces along with the angle
configurations increasing (Fig. 9b) when the nozzle
holder was allowed to move sideways (horizontally, back
and forth) on its axis. The results indicated that the
thickness of nanofibers could be flexible operated by adding
robot-aided system [
A robot electrospinning direct‑clothing device
As mentioned above, the feasibility of producing strong
plasticity and thick nanofibers with mass production is
analyzed based on the principle of robot-assisted angled
multi-nozzle electrospinning. In 2013, Yang et al. [
developed a robot electrospinning device which could be
achieved in the true sense of large-scale production and
apply it on garment industry. An electrospinning robot
(Fig. 10a23), a robot controller (Fig. 10a1), a electrostatic
spinning device (Fig. 10a2), a spinning model device
(Fig. 10c17), a tracking camera (Fig. 10a21), and a
computer control device (Fig. 10a22) altogether consist of the
robot electrospinning direct-clothing device (Fig. 10).
These systems could combine robot technology and
multi-needle electrospinning and is suitable for using on
solution, melt, near-filed electrospinning, and
composite electrospinning. The spinning device can be operated
along a predetermined path by means of a
electrospinning robot induction, feedback, and control combined
with a computer program control, and ensures spinning
sprinkler head is vertically downward. The computer
control device is mainly be responsible for carrying out
data processing and conversion according to the
information taken and transmitted by the tracking camera,
controlling the robot controller at the same time, and
the robot controller accepts the command, directs, and
controls the electric spinning robot to use the
electrospinning device to complete the command indication.
According to the transfer of modified information
feedback, the shape of electrospun model and the spinning
path are modified timely. Therefore, it overcomes the
disadvantage that nanofibers cannot be plasticized and
A rotating robot multi‑nozzle electrospinning device
Different to the two robot-aided ways mentioned
above, a rotating robot multi-nozzle was developed
by controlling fiber intercalation and the number of
fibers involved in the overall multi-fiber structure for
displaying better mechanical characteristics [
and getting the preferred morphological choice for
the textile industries [
]. In 2016, Zhang et al. [
reported a rotating robot multi-nozzle for utilizing to
fabricate continuous ropes and collecting two
intercalated fibers micron-scaled rope fabrication via control
on the diameter and number of twists (per length).
Figure 11 shows that two spinnerets were driven by
rotating motor; the two types of jet formed the twisted
micro-rope in uniform electric field. They found the
using of a rotating robot multi-nozzle directly impacts
the deposition of twisty nanofibers. It overcomes the
undesirable characteristics of nanofibers, such as
poor mechanical strength, low surface roughness, and
resulting structures which are randomly orientated
Conclusion and outlook
Robot-aided electrospinning provides much higher
operation precision and stability, which makes the 3D
construction of nanofibers possible and allows us to design the
nanofiber’s shape according to the actual requirements. Yet,
there are still many challenges that need to be addressed to
make the truly intelligent biomedical engineering. Firstly,
in the electrospinning process, the electrical field is one of
the most parameters, which directly determines the
fabrication accuracy. However, the current robot-aided
electrospinning is mainly focusing the position control, and few is
mentioned the dynamic model of the electrical field. More
theoretical works in electrical field would be very helpful to
establish the model of the electrospinning field. Secondly,
the sensing method to monitor the condition of the
fabricated fiber is still limited. To control the fabrication process
precisely, one important thing is to estimate the product
dynamically. However, in current electrospinning system,
the only thing can do is to image the structure of the
fibers. Other import information, such as the dimeter and
mechanical property, has to be investigated after
fabrication. Such off-line sensing technique brings big challenges
to the real-time robot control. Hence, sensing fusion
techniques that are able to get more information of the biofibers
in real time could promote the system a lot. Lastly, an
effective control strategy for the fabrication process should also
be considered. As discussed above, the fabrication process
is affected by many factors, such as voltage,
nozzle–collector distance, solution, temperature. Considering those
factors are coupled together, we shall build a model and
design a strategy to adjust those parameters dynamically to
achieve the desired result. Unfortunately, up to now, rare
related works have been done, and the mechanism behind
is still not clear. Therefore, more effort should be taken in
In summary, the robot-aided electrospinning is an
emerging highly interdisciplinary field, which required
both the knowledge of robotics and biomedical. In the
future, a deep integration of the general electrospinning
and the robotic should be a way to address the existing
challenges. From the perspective of device design,
controllable design extends the concept of “thinner” design,
aiming at developing products to apply the various biomedical
fields. It is particularly important to develop a simple and
high accuracy of robot-aided electrospinning for saving
time, simple assembling, disassembling, and maintaining.
RT and XY drafted the manuscript. YS gave comments and ideas about the
organization and contents of the article. All authors read and approved the
1 City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, SAR.
2 Centre for Robotics and Automation, CityU Shen Zhen Research Institute,
Shen Zhen, China.
This work was partly supported by Shenzhen (China) Basic Research Project
The authors declare that they have no competing interests.
Availability of data and materials
Any requests for materials should be addressed to Y.S. (email: yajishen@cityu.
This work was partly supported by Shenzhen (China) Basic Research Project
Springer Nature remains neutral with regard to jurisdictional claims in
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1. Frenot A , Chronakis IS . Polymer nanofibers assembled by electrospinning . Curr Opin Colloid Interface Sci . 2004 ; 8 : 64 - 75 .
2. Lin J , Wang X , Ding B , Yu J , Sun G , Wang M. Biomimicry via electrospinning . Crit Rev Solid State Mater Sci . 2012 ; 37 : 94 - 114 .
3. Aytac Z , Yildiz ZI , Kayaci-Senirmak F , Tekinay T , Uyar T. Electrospinning of cyclodextrin/linalool-inclusion complex nanofibers: fast-dissolving nanofibrous web with prolonged release and antibacterial activity . Food Chem . 2017 ; 231 : 192 - 201 .
4. Sajeev US , Anand KA , Menon D , Nair S. Control of nanostructures in PVA, PVA/chitosan blends and PCL through electrospinning . Bull Mater Sci . 2008 ; 31 : 343 - 51 .
5. Subbiah T , Bhat GS , Tock RW , Pararneswaran S , Ramkumar SS . Electrospinning of nanofibers . J Appl Polym Sci . 2005 ; 96 : 557 - 69 .
6. Senturk-Ozer S , Ward D , Gevgilili H , Kalyon DM . Dynamics of electrospinning of poly(caprolactone) via a multi-nozzle spinneret connected to a twin screw extruder and properties of electrospun fibers . Polym Eng Sci . 2013 ; 53 : 1463 - 74 .
7. Kishan AP , Cosgriff-Hernandez EM . Recent advancements in electrospinning design for tissue engineering applications: a review . J Biomed Mater Res A . 2017 ; 105 : 2892 - 905 .
8. Kanani AG , Bahrami SH . Review on electrospun nanofibers scaffold and biomedical applications . Trends Biomater Artif Organs . 2010 ; 24 ( 2 ): 93 - 115 .
9. Meng ZX , Li HF , Sun ZZ , Zheng W , Zheng YF . Fabrication of mineralized electrospun PLGA and PLGA/gelatin nanofibers and their potential in bone tissue engineering . Mater Sci Eng C Mater Biol Appl . 2013 ; 33 : 699 - 706 .
10. Liu LQ , Eder M , Burgert I , Tasis D . One-step electrospun nanofiber-based composite ropes . Appl Phys Lett . 2007 ; 90 : 1624 - 49 .
11. Heikkilä P , Taipale A , Lehtimäki M , Harlin A . Electrospinning of polyamides with different chain compositions for filtration application . Polym Eng Sci . 2008 ; 48 : 1168 - 76 .
12. Meechaisue C , Wutticharoenmongkol P , Waraput R , Huangjing T , Ketbumrung N , Pavasant P , et al. Preparation of electrospun silk fibroin fiber mats as bone scaffolds: a preliminary study . Biomed Mater . 2007 ; 2 : 181 .
13. Wang HL , Zheng GF , Sun DH . Simulation of nanofibers movement for near-field electrospinning . Adv Mater Res . 2009 ; 60 - 61 : 456 - 60 .
14. Zheng G , Li W , Wang X , Wu D , Sun D , Lin L . Precision deposition of a nanofibre by near-field electrospinning . J Phys D Appl Phys . 2010 ; 43 : 415501 .
15. Okuzaki H , Kobayashi K , Yan H . Non-woven fabric of poly(N-isopropylacrylamide) nanofibers fabricated by electrospinning . Synth Met . 2009 ; 159 : 2273 - 6 .
16. Khorshidi S , Solouk A , Mirzadeh H , Mazinani S , Lagaron JM , Sharifi S , et al. A review of key challenges of electrospun scaffolds for tissue-engineering applications . J Tissue Eng Regen Med . 2016 ; 10 : 715 - 38 .
17. Teo WE , Ramakrishna S. Electrospun nanofibers as a platform for multifunctional, hierarchically organized nanocomposite . Compos Sci Technol . 2009 ; 69 : 1804 - 17 .
18. Tian S , Ogata N , Shimada N , Nakane K , Ogihara T , Yu M. Melt electrospinning from poly(l -lactide) rods coated with poly(ethylene-co-vinyl alcohol) . J Appl Polym Sci . 2010 ; 113 : 1282 - 8 .
19. Deng R , Liu Y , Ding Y , Xie P , Luo L , Yang W. Melt electrospinning of lowdensity polyethylene having a low-melt flow index . J Appl Polym Sci . 2010 ; 114 : 166 - 75 .
20. Lian H , Meng Z. Melt electrospinning vs. solution electrospinning: a comparative study of drug-loaded poly (ε-caprolactone) fibres . Mater Sci Eng C Mater Biol Appl . 2017 ; 74 : 117 .
21. Kong CS , Yoo WS , Jo NG , Kim HS . Electrospinning mechanism for producing nanoscale polymer fibers . J Macromol Sci Part B . 2010 ; 49 : 122 - 31 .
22. Sun D , Chang C , Li S , Lin L . Near-field electrospinning . Nano Lett . 2006 ; 6 : 839 .
23. He XX , Zheng J , Yu GF , You MH , Yu M , Ning X , et al. Near-field electrospinning: progress and applications . J Phys Chem C . 2017 ; 121 ( 6 ): 8663 - 78 .
24. Huang Y , Zheng G , Wang X , Sun D. Fabrication of micro/nanometerchannel by near-field electrospinning . In: IEEE international conference on nano/micro engineered and molecular systems; 2011 . p. 877 - 880 .
25. Chang C , Limkrailassiri K , Lin L . Continuous near -field electrospinning for large area deposition of orderly nanofiber patterns . Appl Phys Lett . 2008 ; 93 : 123111 - 3 .
26. Repanas A , Andriopoulou S , Glasmacher B. The significance of electrospinning as a method to create fibrous scaffolds for biomedical engineering and drug delivery applications . J Drug Deliv Sci Technol . 2016 ; 31 : 137 - 46 .
27. Nagy ZK , Balogh A , Drávavölgyi G , Ferguson J , Pataki H , Vajna B , et al. Solvent-free melt electrospinning for preparation of fast dissolving drug delivery system and comparison with solvent-based electrospun and melt extruded systems . J Pharm Sci . 2013 ; 102 : 508 - 17 .
28. Liu SL , Long YZ , Huang YY , Zhang HD , He HW , Sun B , et al. Solventless electrospinning of ultrathin polycyanoacrylate fibers . Polym Chem . 2013 ; 4 : 5696 - 700 .
29. Yang Y , Jia Z , Liu J , Li Q . Effect of electric field distribution uniformity on electrospinning . J Appl Phys . 2008 ; 103 : 89 .
30. Sun Z , Zussman E , Yarin AL , Wendorff JH , Greiner A . Compound core-shell polymer nanofibers by co-electrospinning . Adv Mater . 2003 ; 15 : 1929 - 32 .
31. Kenawy E-R , Abdel-Hay FI , El-Newehy MH , Wnek GE . Processing of polymer nanofibers through electrospinning as drug delivery systems . Mater Chem Phys . 2009 ; 113 : 296 - 302 .
32. Zamani M , Morshed M , Varshosaz J , Jannesari M. Controlled release of metronidazole benzoate from poly epsilon-caprolactone electrospun nanofibers for periodontal diseases . Eur J Pharm Biopharm . 2010 ; 75 : 179 .
33. Jing Z , Xu X , Chen X , Liang Q , Bian X , Yang L , et al. Biodegradable electrospun fibers for drug delivery . J Control Release . 2003 ; 92 : 227 .
34. Jiang H , Hu Y , Li Y , Zhao P , Zhu K , Chen W. A facile technique to prepare biodegradable coaxial electrospun nanofibers for controlled release of bioactive agents . J Control Release . 2005 ; 108 : 237 - 43 .
35. Okuda T , Tominaga K , Kidoaki S . Time-programmed dual release formulation by multilayered drug-loaded nanofiber meshes . J Control Release . 2010 ; 143 : 258 - 64 .
36. Hu X , Liu S , Zhou G , Huang Y , Xie Z , Jing X . Electrospinning of polymeric nanofibers for drug delivery applications . J Control Release . 2014 ; 185 : 12 - 21 .
37. Inozemtseva OA , Salkovskiy YE , Severyukhina AN , Vidyasheva IV , Petrova NV , Metwally HA , et al. Electrospinning of functional materials for biomedicine and tissue engineering . Russ Chem Rev . 2015 ; 84 : 251 - 74 .
38. Hilderbrand AM , Ovadia EM , Rehmann MS , Kharkar PM , Guo C , Kloxin AM . Biomaterials for 4D stem cell culture . Curr Opin Solid State Mater Sci . 2016 ; 20 : 212 - 24 .
39. Sell SA , Wolfe PS , Garg K , McCool JM , Rodriguez IA , Bowlin GL . The use of natural polymers in tissue engineering: a focus on electrospun extracellular matrix analogues . Polymers . 2010 ; 2 : 522 - 53 .
40. Zou B , Liu Y , Luo X , Chen F , Guo X , Li X . Electrospun fibrous scaffolds with continuous gradations in mineral contents and biological cues for manipulating cellular behaviors . Acta Biomater . 2012 ; 8 : 1576 - 85 .
41. Gurtner GC , Callaghan MJ , Longaker MT . Progress and potential for regenerative medicine . Annu Rev Med . 2007 ; 58 : 299 - 312 .
42. Laurencin CT , Ambrosio AM , Borden MD , Cooper J Jr. Tissue engineering: orthopedic applications . Annu Rev Biomed Eng . 1999 ; 1 : 19 .
43. Stevens MM , George JH . Exploring and engineering the cell surface interface . Science . 2005 ; 310 : 1135 - 8 .
44. Agarwal S , Wendorff JH , Greiner A . Use of electrospinning technique for biomedical applications . Polymer . 2008 ; 49 : 5603 - 21 .
45. Dong RH , Jia YX , Qin CC , Zhan L , Yan X , Cui L , et al. In situ deposition of a personalized nanofibrous dressing via a handy electrospinning device for skin wound care . Nanoscale . 2016 ; 8 : 3482 - 8 .
46. Liu NH , Pan JF , Miao YE , Liu TX , Xu F , Sun H . Electrospinning of poly (epsilon-caprolactone-co-lactide)/Pluronic blended scaffolds for skin tissue engineering . J Mater Sci . 2014 ; 49 : 7253 - 62 .
47. Kwak S , Haider A , Gupta KC , Kim S , Kang IK . Micro/nano multilayered scaffolds of PLGA and collagen by alternately electrospinning for bone tissue engineering . Nanoscale Res Lett . 2016 ; 11 : 1 - 16 .
48. Shao WL , He JX , Han QM , Sang F , Wang Q , Chen L , et al. A biomimetic multilayer nanofiber fabric fabricated by electrospinning and textile technology from polylactic acid and Tussah silk fibroin as a scaffold for bone tissue engineering . Mater Sci Eng C Mater Biol Appl . 2016 ; 67 : 599 - 610 .
49. Ercolani E , Del Gaudio C , Bianco A. Vascular tissue engineering of smalldiameter blood vessels: reviewing the electrospinning approach . J Tissue Eng Regen Med . 2015 ; 9 : 861 - 88 .
50. Vaz CM , van Tuijl S , Bouten CVC , Baaijens FPT . Design of scaffolds for blood vessel tissue engineering using a multi-layering electrospinning technique . Acta Biomater . 2005 ; 1 : 575 - 82 .
51. Ehler E , Jayasinghe SN . Cell electrospinning cardiac patches for tissue engineering the heart . Analyst . 2014 ; 139 : 4449 - 52 .
52. Kitsara M , Agbulut O , Kontziampasis D , Chen Y , Menasche P. Fibers for hearts: a critical review on electrospinning for cardiac tissue engineering . Acta Biomater . 2017 ; 48 : 20 - 40 .
53. Szentivanyi AL , Zernetsch H , Menzel H , Glasmacher B . A review of developments in electrospinning technology: new opportunities for the design of artificial tissue structures . Int J Artif Organs . 2011 ; 34 : 986 - 97 .
54. Basu P , Repanas A , Chatterjee A , Glasmacher B , NarendraKumar U , Manjubala I. PEO-CMC blend nanofibers fabrication by electrospinning for soft tissue engineering applications . Mater Lett . 2017 ; 195 : 10 - 3 .
55. Kim S , Park S-G , Kang S-W , Lee KJ . Nanofiber-based hydrocolloid from colloid electrospinning toward next generation wound dressing . Macromol Mater Eng . 2016 ; 301 : 818 - 26 .
56. Mele E. Electrospinning of natural polymers for advanced wound care: towards responsive and adaptive dressings . J Mater Chem B . 2016 ; 4 : 4801 - 12 .
57. Mogoşanu GD , Grumezescu AM . Natural and synthetic polymers for wounds and burns dressing . Int J Pharm . 2014 ; 463 : 127 .
58. Boateng JS , Matthews KH , Stevens HN , Eccleston GM . Wound healing dressings and drug delivery systems: a review . J Pharm Sci . 2008 ; 97 : 2892 .
59. Melaiye Abdulkareem , Sun Zhaohui, Hindi Khadijah, Milsted Amy, Ely Daniel, Reneker DH , et al. Silver (I) -imidazole cyclophane gem-diol complexes encapsulated by electrospun tecophilic nanofibers: formation of nanosilver particles and antimicrobial activity . J Am Chem Soc . 2005 ; 127 : 2285 - 91 .
60. Hong KH . Preparation and properties of electrospun poly(vinyl alcohol)/ silver fiber web as wound dressings . Polym Eng Sci . 2007 ; 47 : 43 - 9 .
61. Wei Q , Xu F , Xu X , Geng X , Ye L , Zhang A , et al. The multifunctional wound dressing with core-shell structured fibers prepared by coaxial electrospinning . Front Mater Sci . 2016 ; 10 : 113 - 21 .
62. Dickinson LE , Gerecht S. Engineered biopolymeric scaffolds for chronic wound healing . Front Physiol . 2016 ; 7 : 341 .
63. Kennedy KM , Bhaw-Luximon A , Jhurry D. Skin tissue engineering: biological performance of electrospun polymer scaffolds and translational challenges . Regener Eng Transl Med . 2017 ; 1 - 14 .
64. Ding Z , Salim A , Ziaie B . Selective nanofiber deposition through fieldenhanced electrospinning . Langmuir . 2009 ; 25 : 9648 .
65. Ying Yang ZJ , Li Qiang , Hou Lei, Liu Jianan, Wang Liming, Guan Zhicheng . A shield ring enhanced equilateral hexagon distributed multi-needle electrospinning spinneret . IEEE Trans . 2010 ; 17 : 1010 - 9878 .
66. Han W , Minhao L , Xin C , Junwei Z , Xindu C , Ziming Z. Study of deposition characteristics of multi-nozzle near-field electrospinning in electric field crossover interference conditions . AIP Adv . 2015 ; 5 : 041302 .
67. Kim IG , Lee J-H , Unnithan AR , Park C-H , Kim CS. A comprehensive electric field analysis of cylinder-type multi-nozzle electrospinning system for mass production of nanofibers . J Ind Eng Chem . 2015 ; 31 : 251 - 6 .
68. Li D , Babel A , Jenekhe SA , Xia YN . Nanofibers of conjugated polymers prepared by electrospinning with a two-capillary spinneret . Adv Mater . 2004 ; 16 : 2062 - 6 .
69. McKee MG , Wilkes GL , Colby RH , Long TE . Correlations of solution rheology with electrospun fiber formation of linear and branched polyesters . Macromolecules . 2004 ; 37 : 1760 - 7 .
70. Pant HR , Bajgai MP , Yi CA , Nirmala R , Nam KT , Baek WI , et al. Effect of successive electrospinning and the strength of hydrogen bond on the morphology of electrospun nylon-6 nanofibers. Colloid Surf A Physicochem Eng Asp . 2010 ; 370 : 87 - 94 .
71. Zheng G , Sun L , Wang X , Wei J , Xu L , Liu Y , et al. Electrohydrodynamic direct-writing microfiber patterns under stretching . Appl Phys A . 2016 ; 122 ( 2 ): 112 .
72. Park CH , Kim C-H , Pant HR , Tijing LD , Yu MH , Kim Y , et al. An angled robotic dual-nozzle electrospinning set-up for preparing PU/PA6 composite fibers . Text Res J . 2012 ; 83 : 311 - 20 .
73. Park CH , Pant HR , Kim CS . Novel robot-assisted angled multi-nozzle electrospinning set-up: computer simulation with experimental observation of electric field and fiber morphology . Text Res J . 2014 ; 84 : 1044 - 58 .
74. Yao Z-C , Yuan Q , Ahmad Z , Huang J , Li J-S , Chang M-W. Controlled morphing of microbubbles to beaded nanofibers via electrically forced thin film stretching . Polymers . 2017 ; 9 : 265 .
75. Yang WLZ , Zhang L , Zhang Y , Li H , Chen H , Liu X , Chen M , Zhong X , Ding Y ( 2013 ) Robot eletrospinning direct-clothing device . CN Patent 201310152805:A, 17 July 2013 .
76. Zhang C , Gao C , Chang M-W , Ahmad Z , Li J-S . Continuous micron-scaled rope engineering using a rotating multi-nozzle electrospinning emitter . Appl Phys Lett . 2016 ; 109 : 151903 .
77. He JH , Yu YP , Yu JY , Li WR , Wang SY , Pan N. A nonlinear dynamic model for two-strand yarn spinning . Text Res J . 2005 ; 75 : 181 - 4 .
78. Shuakat MN , Lin T . Highly-twisted, continuous nanofibre yarns prepared by a hybrid needle-needleless electrospinning technique . Rsc Adv . 2015 ; 5 : 33930 - 7 .
79. John J , Shantikumar VN , Deepthy M. Integrating substrateless electrospinning with textile technology for creating biodegradable threedimensional structures . Nano Lett . 2015 ; 15 : 5420 .
80. Shah DU , Schubel PJ , Clifford MJ . Modelling the effect of yarn twist on the tensile strength of unidirectional plant fibre yarn composites . J Compos Mater . 2012 ; 47 : 425 - 36 .
81. He J , Zhou Y , Qi K , Wang L , Li P , Cui S. Continuous twisted nanofiber yarns fabricated by double conjugate electrospinning . Fibers Polym . 2013 ; 14 : 1857 - 63 .