Www.tango.net R J Download

Self-folding is the ability of the structure to fold and/or unfold without human intervention or any application of external manipulation. It is known that the structure of folding object consists of two essential parts. These parts are the faces and the creases. In this paper, it is assumed that the faces could be built by using solid materials, and the crease lines can be built using soft material which provides a high bent ability. Furthermore, these two materials should be combined built without using any connections between them. Fortunately, the 3D printer provides this capability. It can print two types of different materials at the same time for the same structure. Therefore, a 3D printer is chosen to fabricate a folding structure using two types of material. These types are the Vero for solid faces and Tango plus FLX930 for the soft creases lines. The soft material at hinge part (creases lines) subjected to the load directly when the structure folds. It should have a clear view of the mechanical properties of this material. Therefore, several mechanical tests for Tango FLX930 material are operated to calculate its mechanical properties and find the force that required to fold it.

Figures - uploaded by Akeel A. Abtan

Author content

All figure content in this area was uploaded by Akeel A. Abtan

Content may be subject to copyright.

Discover the world's research

• 20+ million members
• 135+ million publications
• 700k+ research projects

Join for free

Analyzing the 3D Printed Material Tango Plus

FLX930 for Using in Self-Folding Structure

Akeel A. Abtan

E-mail: mnaaabt@leeds.ac.uk

Robert C. Richardson

E-mail: R.C.Richardson@leeds.ac.uk

Briony Thomas

E-mail: B.G.Thomas@leeds.ac.uk

School of Mechanical Engineering

University of Leeds

Leeds, UK.

Abstract— Self-folding is the ability of the structure to fold

and/or unfold without human intervention or any application of

external manipulation. It is known that the structure of folding

object consists of two essential parts. These parts are the faces

and the creases.

In this paper, it is assumed that the faces could be built by

using solid materials, and the crease lines can be built using soft

material which provides a high bent ability. Furthermore, these

two materials should be combined built without using any

connections between them. Fortunately, the 3D printer provides

this capability. It can print two types of different materials at the

same time for the same structure. Therefore, a 3D printer is

chosen to fabricate a folding structure using two types of

material. These types are the Vero for solid faces and Tango plus

FLX930 for the soft creases lines. The soft material at hinge part

(creases lines) subjected to the load directly when the structure

folds. It should have a clear view of the mechanical properties of

this material. Therefore, several mechanical tests for Tango

FLX930 material are operated to calculate its mechanical

properties and find the force that required to fold it.

Keywords— Self-Folding Structure; 3D printer; Tango Plus.

I. I

NTRODUCTION

The self-folding structure gives the opportunity to

manufacture many types of robots as a plane sheet. This sheet

can fold itself during the task operation. The folding robots are

inspired from the "origami" which is the Japanese's word that

means the art of folding papers. In the last few years, some

researchers consider the origami robots and self-folding sheet

to be potential solutions for the applications that require a

morphing structure [1], [2]. The ambition of these researchers

is to reach the design of robot with a high degree of freedom

which is simple manufacturing and inexpensive. In addition, it

can be self-folding, and self-assembly and it can be used to

operate a minimally invasion task in surgery or search and

rescue mission because it is folded from a 2D sheet into a 3D

structure.

However, there are no real applications of folding robots in

search and rescue field except the two papers by Lee that

present a prototype of rescue robots using origami wheels. Lee

designed two robots with deformable wheels using the origami

magic ball pattern to fabricate the wheels [3],[4]. The two

robots using a folding structure to fabricate a simple part of the

robot, but the unique characteristics of folding open the future

to many unexpected designs that can be adopted in many

robotic fields.

The two major categories of folding material depending on

the folding process which are the manual folding and self-

folding robots. These two categories depend on the same steps

to fabricate the folding robots which are: (1) planner and

design the pattern, (2) select materials and fabrication

procedure, and (3) choose the actuators that operate the motion

or locomotion in manual folding robots or operate the self-

folding and locomotion in the self-folding robots. The

researchers focus on how to fabricate simple, cheap and fast

fabrication robots by using a folding approach. While in self-

folding, the researchers focus on morphing the 2D sheet into

3D structure at the operation task or how can build

reconfiguration robots by using folding approach.

Some researchers build a printable robot using paper and

folding it manually [5], [6]. Other researchers developed a self-

folding hinges by using multilayer laminate which consist of

shape memory polymer SMP, paper or plastic sheet, and

resistive circuits [7]. They used an outer layer of SMP from

two sides. This self- folding technique shows the capability of

creating complex geometries. They fabricated a printed

inchworm robot [8] by using this self-folding approach.

Recently, they developed a crawling robot that folds itself by

using five layers. These layers are two outer SMP layers, two

paper layers and the middle layer of the copper-polyimide [2].

This paper focuses on the material that could build a

folding structure. It is assumed that the folding structure could

be easily fabricated using the 3D printer. The 3D printer can

print a sheet with solid faces and soft material for the hinges.

Therefore, it is chosen the Vero material to be the solid faces

and Tango Plus FLX930 to be the soft material. For that

reason, the Tango Plus FLX930 should be analyzed to calculate

its mechanical behavior such as tensile, bending, and fatigue.

II. O

RIGAMI AND

F

OLDING

S

TRUCTURE

All folding structures are inspired from origami which is

the art of paper folding. The essential difference is that the

folding structure could be made from any material, while the

paper is the major material for origami structure. However, all

the structural design of any folder structure can be obtained by

using the principals of origami design pattern.

The creases are the singularity part in folding structure and

should build from soft material. The creases are the locations

of localized folds of the sheet. Every crease can be folded

either convex (mountain ) or concave (valley ). The vertices are

the endpoints of the crease lines. The faces are the closed areas

that bounded by the creases and it should be built from hard

material. All the creases with its mountain and valley

assignments make up the crease pattern . These concepts are

shown in Fig. 1. The Vero is chosen for solid faces and Tango

plus FLX930 is chosen for the soft creases lines to fabricate the

folding structure using 3D printer.

The Tessellation origami is the appropriate type of origami

shape to produce the folding robot because this type has a high

flexibility and can be reconfigurable after folding. These two

properties are very important to the functionality of robots.

Furthermore, the crease patterns of this type consist a similar

element that can repeat forever to form structures on any scale.

This property makes it easy to put actuation procedure for one

element and repeat it for all other elements. The best examples

of Tessellation origami are origami magic ball. The major

features which provide by this design is that, the magic ball can

contract and expand in all directions See Fig. 2.

One element of magic ball structure was printed by using

3D printer see Fig. 3. The element has a square shape with 20

mm length and 1mm thickness. The creases lines have width of

2mm which are made from Tango Plus FLX 930. The strain in

the creases is analyzed before these dimensions are chosen.

Fig. 1. Crease pattern illustrating various origami concepts.

Fig. 2. (a) Crease patterns of Magic Ball, (b) Origami Magic Ball after

folding [9].

Fig. 3. One element from the magic ball pattern Manufacturing by 3D

printer

III. S

TRAIN IN THE CREASES

All the deformation for any origami structures occurs on

the crease line. Whatever it is a mountain or valley crease. We

should have a clear description of this area to achieve a correct

design. When the crease line is analyzed for any material (not

just paper), it should be assumed that the crease line work as a

hinge connected other solid material. This hinge has two

effective dimensions which are the width b and the thickness t.

Every crease has a radius of curvature R and folding angle θ i

when it is bent. From these parameters, the strain ε at any

point on the edge can be calculated as:



 





 (1)

Where r is the variable radius and its value: (R ≤ r ≤ R + t)

and l is the length.

By assuming that the maximum fold occurs when the two

inner sides of a hinge attached, see Fig. 4. In this special case,

the radius assumed to be equal to the thickness and the

maximum strain on the outer surface of the hinge can be

calculated as:

ε 

 (2)

It can be seen from equation (2) that the maximum strain on

the creases tip directly proportional to the thickness and

inversely proportional to the width. For example, if there is a

square hinge (i.e. b=t) the maximum strain is π . Therefore, the

mechanical tests should be operated for the Tango Plus

FLX930 material to ensure that the maximum strain does not

exceed by tension, bending and fatigue.

Fig. 4. Simple sketch of a hinge with width b, and thickness t . Starting

from flat shape until it is completely fold.

IV. M

ECHANICAL

T

ESTS AND

R

ESULTS

Mechanical properties can demonstrate the behavior of the

materials and give the answer of the question for using this

material for fabrication crease lines in folding robots or not.

Our case requires several mechanical tests such as tensile test,

bending test and fatigue test for the Tango Plus flx930 material.

These three tests can show the results for the tensile strength

limit, fatigue limit and the forces require to fold different

thickness sheets into many folding angles.

A. Tensile Test

Although, the tensile test is a traditional mechanical test

and there are many standards which show the modulus of

elasticity and the tensile strength of different materials, there is

lack information about tensile strength for elastomer materials

especially for the materials using 3D printer.

Moreover, it is very hard to calculate the modulus of

elasticity for elastomer materials analytically, because of many

issues such as large deformation response, and non-linearity of

the stress-strain curve [10]. Therefore, every new elastomer

material should have a particular tensile test to indicate their

properties. Although, some elastomer properties depend on

time due to the hysteresis effect, this test can give us suitable

induction for these properties.

The tensile test was operated three times for three

specimens which have the same shape. The specimen has a

cylindrical shape with effective length and area (37.7mm,

39.92 mm2) respectively. All specimens were printed on an

Object-1000 3D printer in "digital material" mode. The final

specimen shape can be seen in the Fig. 5.

The test velocity was set at 60 mm/min. After that, the test

was operated which took almost two minutes for every

specimen. The stress-strain curve can be calculated from the

data of load-displacement which was collected from the tensile

test machine. It can be determined by using traditional

equations of stress σ and strain which are:

σ 





(3)

∆





 (4)

Where, Ae and Le are the effective area and length.

The stress-strain curve can be seen in the Fig. 6. This figure

shows the stress-strain curve for the three specimens, and it is

clear that the tensile strength of the first specimen equal to 0.68

Mpa and the maximum elongation is 260%. For all specimens,

the tensile strength range is between 0.63-0.68 Mpa and the

maximum elongation range is between 250-260% and that is

nearly the standard that given for this material.

Fig. 5. The tensile test specimen made from Tango Plus flx930.

Fig. 6. The stress-strain curve for Tango Plus flx930.

B. Bending Test

The important useful information, which is required from

the material behavior, is the amount of force that could fold the

sheet made from this material. Therefore, this test can find the

amount of force which required folding different thickness

beams into a range of folding angles.

Flat specimens are used for this test which have a beam

shape. The dimensions of these specimens are 40mm length

and 10mm width with three different thicknesses which are

3mm, 5mm, and 7mm. In addition, two types of specimens are

used for the 5mm thickness; the first one is completely flat, and

the other one has a notch on both sides in the middle with 1mm

radius, see Fig. 7. The reason for using these specimens is to

find the relation between the thickness and the folding force.

Furthermore, these specimens can show the effect of the notch

on the folding force. The machine, which was used for this test,

is the tensile machine with the graspers of three-point bending

test. These graspers used to calculate the material resistant to

bending damage. We change the middle rod of this grasper,

which is 6mm thick, with the smaller wire, which is 1mm in

diameter, to make the folding angle sharp and to reach a

smaller radius of curvature for the folding specimen. The test

machine requires the speed of test and the final displacement to

stop. For our situation, we used the speed of test 60 mm/min

and the final displacement 20mm.

When the folding angles are calculated, it is found that

there are drooping in load after the angles 105o , 120o , 125o and

135o for the thickness 3mm, 5mm with a notch, 5mm and 7mm

respectively. This drooping in load due to the slipping of

specimens from grasper rod sides when reaching these angles.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

00.511.522.53

Stress(N/mm^2)

Strain

Specimen #1

Specimen #2

Specimen #3

Therefore, the relationship between the folding angles and

loads is drawn as it is seen in the Fig. 8, and canceled the

slipping zone.

It can be seen from the Fig. 8 that the load increase when

the thickness increase, but in the same behavior and that is

clear from the slopes of the curves. Furthermore, it can be seen

that the result for the specimen 3 (5mm thickness with notch)

does not decrease the load a lot. Although, it has a 3mm

thickness between the notches, its load does not reach the load

of specimen 1 (3mm thickness).

C. Fatigue test

The fatigue life limited is very active parameter when the

material is used in an operation that have a dynamic load. In

origami structure, the material in the hinge subjected to

repeated load which is produced by folding and unfolding

process. Therefore, the fatigue limit for the Tango Plus

FLX930 should be calculated by using the fatigue test.

Especially, when there is lack information for the fatigue life of

the 3D printed materials. The fatigue test was operated for

three specimens with three different elongation magnitude

(30%, 60% and 100%). The specimens were designed

according to the ASTM standard ASTM D4482-11, 2011. The

final specimen shape that printed on an object-1000 3D printer

can be seen in the Fig. 9.

Fig. 7. The bending test specimens made from Tango Plus flx930.

Fig. 8. The folding angles -loads curves for different thickness specimens.

Fig. 9. The fatigue test specimen made from Tango Plus flx930.

The test was operated three times for three specimens with

different elongation (i.e., the elongation is the maximum

extension input to the machine). The loading and relaxation

cycle was taken from the ASTM standard. This standard

specified a testing frequency of 1.7 Hz. The results taken from

fatigue machine are (6992 cycles, 3640 cycles and 1861 cycles)

for the strains (0.32, 0.6, and 1) respectively. From these results

it can obtain the equation of fatigue life:

N











(5)

Where N is the fatigue life in a number of cycles, εa is the

actual strain and εo & k are the constants of the equation. In our

case, we can calculate the constants as (εo =732 and k= -1.14).

Therefore, the equation of fatigue life for the Tango Plus

FLX930 will be:

N



 -.

(6)

Furthermore, it can obtain the ε -N curve from the results

which represent the strain vs fatigue life for the Tango Plus

FLX930. See Fig. 10.

Fig. 10. ε -N curve for the Tango Plus FLX930.

0

1

2

3

4

5

6

7

8

9

10

0 20406080100120140

Load (N)

Folding angle (Degree)

Specimen1 (3mm thickness)

Specimen2 (5mm thickness)

Specimen3 (5mm thickness) with notch

Specimen4 (7mm thickness)

0

0.2

0.4

0.6

0.8

1

1.2

1861 3640 6992

Actual Strain

N (Cycles)

Test results

Fatigue Equation

V. C

ONCLUSIONS

In this paper, it is assumed that the folding structure can be

printed on the 3D printer using the Vero material for surfaces

and Tango Plus FLX930 for the hinges. The strain and stress

can be determined in these hinges by assuming them as a beam

and using mechanical principles equations. However, the

mechanical properties of the material at that hinge must be

calculated by mechanical tests.

The mechanical tests for Tango plus improve that this

material can be used as a hinge for the folding structure.

Furthermore, it has a high range of elongations that can give

the folding structure more flexibility. The fatigue limit is

calculated, and it is shown that this material can be used in

high dynamic load with the strain limit 0.226. In addition, the

bending test gives the data that could used to calculate the force

required for folding this material into different folding angles.

R

EFERENCES

[1] Onal, C.D., Wood, R.J. and Rus, D. "An origami-inspired approach to

worm robots". Mechatronics, IEEE/ASME Transactions on. 2013, vol.

18, No. 2, pp.430-438.

[2] Felton, S., Tolley, M., Demaine, E., Rus, D. and Wood, R. "A method

for building self-folding machines". Science. 2014, vol. 345, No. 6197,

pp.644-646.

[3] Lee, D.-Y., Kim, J.-S., Kim, S.-R., Park, J.-J. and Cho, K.-J. "Design of

deformable-wheeled robot based on origami structure with shape

memory alloy coil spring". In: Ubiquitous Robots and Ambient

Intelligence (URAI), 2013 10th International Conference on: IEEE,

2013, pp.120-120.

[4] Lee, D.-Y., Kim, J.-S., Park, J.-J., Kim, S.-R. and Cho, K.-J.

"Fabrication of origami wheel using pattern embedded fabric and its

application to a deformable mobile robot". In: Robotics and Automation

(ICRA), 2014 IEEE International Conference on: IEEE, 2014, pp.2565-

2565.

[5] Hoff, E.V., Jeong, D. and Lee, K. OrigamiBot-I: "A thread-actuated

origami robot for manipulation and locomotion". In: Intelligent Robots

and Systems (IROS 2014), 2014 IEEE/RSJ International Conference on:

IEEE, 2014, pp.1421-1426.

[6] Zhang, K., Qiu, C. and Dai, J.S." Helical Kirigami-Inspired Centimeter-

Scale Worm Robot With Shape-Memory-Alloy Actuators". In: ASME

2014 International Design Engineering Technical Conferences and

Computers and Information in Engineering Conference: American

Society of Mechanical Engineers, 2014, pp.V05BT08A039-

V005BT008A039.

[7] Felton, S.M., Tolley, M.T., Onal, C.D., Rus, D. and Wood, R.J. "Robot

self-assembly by folding: A printed inchworm robot". In: Robotics and

Automation (ICRA), 2013 IEEE International Conference on: IEEE,

2013, pp.277-282.

[8] Felton, S.M., Tolley, M.T., Shin, B., Onal, C.D., Demaine, E.D., Rus, D.

and Wood, R.J. "Self-folding with shape memory composites". Soft

Matter. 2013, vol. 9, No. 32, pp.7688-7694.

[9] https://www.flickr.com/photos/26201012@N02/5411813561

[10] Judson, T.B. "Rubber Stress-Strain Behavior. In: Fatigue, Stress, and

Strain of Rubber Components". Carl Hanser Verlag GmbH & Co. KG,

2008, pp.9-18.

... The aim of this study is the creation of a 3D physical model made by elastomer (Tango Plus, Stratasys, Israel) through the AM technique to allow clip selection prior to surgery. This material brings more realism to the biomodels due to its mechanical properties-being flexible enough to allow simulation of the procedure (24). The clip selection involves not only the choice of the surgical clip (size and shape) but also its handling before the real clip implantation (i.e., before the surgery) for safety and effectiveness in the surgical procedure and to reduce the need for preoperative invasive examinations. ...

One of the main difficulties in intracranial aneurysms (IA) surgery refers to the choice of the appropriate clip(s) to be implanted. Although the imaging exams currently available ensure visualization of IA's morphology, they do not bring an accurate reference positioning for the surgeon in executing the surgery procedure nor efficiently contribute to planning the surgery. Unfortunately, for IA's largely inaccessible regions, there is not an efficient method of treatment planning. Therefore, we propose a novel method that allows the generation of a 3D biomodel of the IA region under investigation using additive manufacturing technology (AM). Thus, a physical copy of the IA is produced and offers the surgeon a full view of the anatomy of that region of the brain. The aim of this study is the creation of a flexible 3D physical model (elastomer) through the AM technique, in order to allow the clip selection prior to the surgery. DICOM angio‐CT images from eight patients who underwent IA surgery were transformed into STL format and then built on a 3D printer. Preoperative surgical clip selection was performed and then compared with those used in surgery. At the end of the study, all 3D IA biomodels were reproduced for microsurgical clipping selection and it was possible to predict the metal clip to be used in the surgery. In addition, the proposed methodology helps to clarify the surgical anatomy and to avoid excessive manipulation of the intracranial arteries and prolonged surgical time. The major advantage of this technology is that the surgeon can closely study complex cerebrovascular anatomy from any perspective using realistic 3D biomodels, which can be handheld, allowing simulation of intraoperative situations and anticipation of surgical challenges.

• Minseok Gwon
• Gyubeom Park
• Dongpyo Hong
• Je-sung Koh

Conventional industrial grippers that grip a flat object generally hold objects by using suction or electrostatic force. However, these grippers have limitations when gripping thin, flat, and flexible objects, such as films and flexible printed circuit boards (FPCBs), due to their undefined shape and high flexibility. This paper proposes a soft gripper that can grip flexible and thin objects by utilizing directional adhesives and a compliant mechanism. The directional adhesive pad is fabricated by a three-dimensional (3D) printing process for cost-effective and environment-friendly manufacturing. However, fabrication by 3D printing has disadvantages in terms of the quality of the adhesive surface. An additional coating process presented in this study compensates for the low resolution of 3D printing by improving smoothness. Moreover, an additional coating process is a simple approach for developing directional adhesives with enhanced adhesion strength by deforming the tip shape without a sophisticated fabrication process. The adhesion of adhesives with curved pillars is enhanced compared to adhesives with simple wedge-shaped pillars. The maximum normal adhesion force of the gripper is measured to be 0.47 N (1.57 kPa), and 95% of the initial adhesion is retained after ten thousand attachment/detachment cycles. The adhesion force can be recovered by the cleaning process when the contaminant is attached to the adhesive. The final demonstration shows that the gripper can handle various objects for potential applications such as in green-environmental industries.

The wormlike robots are capable of imitating amazing locomotion of slim creatures. This paper presents a novel centimeter-scale worm robot inspired by a kirigami parallel structure with helical motion. The motion characteristics of the kirigami structure are unravelled by analyzing the equivalent kinematic model in terms of screw theory. This reveals that the kirigami parallel structure with three degrees-of-freedom (DOF) motion is capable of implementing both peristalsis and inchworm-type motion. In light of the revealed motion characteristics, a segmented worm robot which is able to imitate contracting motion, bending motion of omega shape and twisting motion in nature is proposed by integrating kirigami parallel structures successively. Following the kinematic and static characteristics of the kirigami structure, actuation models are explored by employing the linear shape-memory-alloy (SMA) coil springs and the complete procedure for determining the geometrical parameters of the SMA coil springs. Actuation phases for the actuation model with two SMA springs are enumerated and with four SMA springs are calculated based on the Burnside's lemma. In this paper, a prototype of the worm robot with three segments is presented together with a paper-made body structure and integrated SMA coil springs. This centimeter-scale prototype of the worm robot is lightweight and can be used in confined environments for detection and inspection. The study presents an interesting approach of integrating SMA actuators in kirigami-enabled parallel structures for the development of compliant and miniaturized robots.

Origami-inspired manufacturing can produce complex structures and machines by folding two-dimensional composites into three-dimensional structures. This fabrication technique is potentially less expensive, faster, and easier to transport than more traditional machining methods, including 3-D printing. Self-folding enhances this method by minimizing the manual labor involved in folding, allowing for complex geometries and enabling remote or automated assembly. This paper demonstrates a novel method of self-folding hinges using shape memory polymers (SMPs), paper, and resistive circuits to achieve localized and individually addressable folding at low cost. A model for the torque exerted by these composites was developed and validated against experimental data, in order to determine design rules for selecting materials and designing hinges. Torque was shown to increase with SMP thickness, resistive circuit width, and supplied electrical current. This technique was shown to be capable of complex geometries, as well as locking assemblies with sequential folds. Its functionality and low cost make it an ideal basis for a new type of printable manufacturing based on two-dimensional fabrication techniques.

The unique characteristics of origami to realize 3-D shape from 2-D patterns have been fascinating many researchers and engineers. This paper presents a fabrication of origami patterned fabric wheels that can deform and change the radius of the wheels. PVC segments are enclosed in the fabrics to build a tough and foldable structure. A special cable driven mechanism was designed to allow the wheels to deform while rotating. A mobile robot with two origami wheels has been built and tested to show that it can deform its wheels to overcome various obstacles.

• Samuel M. Felton
• Michael Tolley
• Erik D. Demaine
• R. Wood

Origami can turn a sheet of paper into complex three-dimensional shapes, and similar folding techniques can produce structures and mechanisms. To demonstrate the application of these techniques to the fabrication of machines, we developed a crawling robot that folds itself. The robot starts as a flat sheet with embedded electronics, and transforms autonomously into a functional machine. To accomplish this, we developed shape-memory composites that fold themselves along embedded hinges. We used these composites to recreate fundamental folded patterns, derived from computational origami, that can be extrapolated to a wide range of geometries and mechanisms. This origami-inspired robot can fold itself in 4 minutes and walk away without human intervention, demonstrating the potential both for complex self-folding machines and autonomous, self-controlled assembly.

In this research, a novel concept of a deformable wheel robot using the origami structure is proposed. The word, origami, comes from the traditional Japanese art of paper folding. The unique characteristic of origami that realizes three-dimensional structures from two-dimensional materials have long attracted attention from various fields such as design, education and mathematics [1-6]. Among many researches on engineering applications of origami, some suggest that origami structure can be treated as a kinematic system [7-8]. The research in this paper focus on this characteristic - origami structure is a morphing structure, but it is kinematically designable and can be used as mechanical system. The research present how to deal with three major issues in this topic - pattern design, fabrication and actuation - when the deformable wheel mechanism is realized. The pattern design is key design parameter in determining the function of the mechanism. Desired function can be achieved by appropriate design of pattern. Specially designed magic-ball pattern was developed for achieving desired function. Material and fabrication are also important issue. Depending on the material and the fabrication method, the properties of final origami structure are determined. Therefore, to realize desired functionality of final origami structure, appropriate fabrication method should be selected as well as origami pattern need to be designed properly. In this robot, paper coated with Kapton film and pattern by laser machine was used. Third is actuation design. The wheel structure should be rotate and also has limited space. Shape memory alloy coil spring with slip ring was used for this purpose. Integration of solutions of each issues goes to final product of the deformable wheel robot as in figure 1. It shows adoptability with environment that the diameter of the wheel is 70-mm in normal state but by deforming of the wheel, the robot can pass through the 55-mm slit. The result of the r- search shows the possibility that origami structure can be a mechanical system.

Printing and folding are fast and inexpensive methods for prototyping complex machines. Self-assembly of the folding step would expand the possibilities of this method to include applications where external manipulation is costly, such as micro-assembly, mass production, and space applications. This paper presents a method for self-folding of printed robots from two-dimensional materials based on shape memory polymers actuated by joule heating using embedded circuits. This method was shown to be capable of sequential folding, angle-controlled folds, slot-and-tab assembly, and mountain and valley folds. An inchworm robot was designed to demonstrate the merits of this technique. Upon the application of sufficient current, the robot was able to fold into its functional form with fold angle deviations within six degrees. This printed robot demonstrated locomotion at a speed of two millimeters per second.

• C.D. Onal
• Robert J. Wood
• Daniela Rus

This paper presents an origami-inspired technique which allows the application of 2-D fabrication methods to build 3-D robotic systems. The ability to design robots as origami structures introduces a fast and low-cost fabrication method to modern, real-world robotic applications. We employ laser-machined origami patterns to build a new class of robotic systems for mobility and manipulation. Origami robots use only a flat sheet as the base structure for building complicated bodies. An arbitrarily complex folding pattern can be used to yield an array of functionalities, in the form of actuated hinges or active spring elements. For actuation, we use compact NiTi coil actuators placed on the body to move parts of the structure on-demand. We demonstrate, as a proof-of-concept case study, the end-to-end fabrication and assembly of a simple mobile robot that can undergo worm-like peristaltic locomotion.

Source: https://www.researchgate.net/publication/309572169_Analyzing_the_3D_Printed_Material_Tango_Plus_FLX930_for_Using_in_Self-Folding_Structure

Posted by: briefcase456.blogspot.com