A self-packaged stretchable electrode and a preparation method thereof

Abstract

The application relates to a self-packaging stretchable electrode preparation method, which comprises the following steps: step one, adding an oily packaging material and a non-ionic surfactant into a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous dispersion solution; step two, stirring the solution obtained in step one to obtain a uniformly dispersed poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and oily packaging material blended solution; step three, adding a solidified packaging material corresponding to the oily packaging material into the blended solution in step two, and stirring to obtain a printing ink; and step four, printing an electrode by means of electrofluid jet printing, and separating the two phases after standing to form an electrode layer and a packaging layer. The application innovates the electrode assembly process by preparing a flexible stretchable electrode capable of self-packaging, so as to solve the problems of high economic and time cost of a multilayer packaging process. Meanwhile, the electrode is changed from a composite state to a separated state, the electrode line width can be further refined, the electrode stability can be improved, and the electrode pattern can be easily refined.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flexible electronic devices, and particularly relates to a self-packaged stretchable electrode and a preparation method thereof. BACKGROUND

[0002] The existing electrode packaging technology mainly relies on chemical deposition or multi-layer printing method, which can achieve certain protection effect, but has defects such as complex process, high cost, insufficient flexibility and adaptability. For example, the chemical deposition method needs high-vacuum equipment and the packaging layer is easy to peel off due to rigidity, the multi-layer printing method has low efficiency and weak interfacial bonding force, and it is difficult to meet the stability demand under dynamic deformation. In addition, high-resolution patterning often leads to performance degradation due to defects in the packaging layer. SUMMARY

[0003] The application aims to solve the problems of the prior art and provides a self-packaged stretchable electrode and a preparation method thereof.

[0004] The preparation method of the self-packaged stretchable electrode provided by the application comprises the following steps:

[0005] Step one: adding an oily packaging material and a non-ionic surfactant into a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) aqueous dispersion solution;

[0006] Step two: stirring the solution obtained in step one to obtain a uniformly dispersed poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and oily packaging material blended solution;

[0007] Step three: adding a solidified packaging material corresponding to the oily packaging material into the blended solution of step two, and stirring to obtain a printing ink;

[0008] Step four: printing the electrode by electrohydrodynamic jet printing, and then allowing the two phases to separate to form an electrode layer and a packaging layer;

[0009] Step five: heating the obtained electrode in an oven at 40-80 DEG C for 0.5-2 hours to obtain a self-packaged stretchable electrode.

[0010] Further, in step one, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) aqueous dispersion solution accounts for 30%-40% of the total mass of the solution.

[0011] Further, in step one, the oily packaging material is Ecoflex A silicone, Ecoflex B silicone or polydimethylsiloxane (PDMS); and in step three, the solidified packaging material is Ecoflex B silicone, Ecoflex A silicone or a platinum catalytic curing agent. The solidified packaging material is different from the oily packaging material.

[0012] Further, in the step one, Triton X-100 accounts for 2%-2.25% of the total mass of the solution.

[0013] Further, in the step two, the stirring is at 300 r / min magnetic force for half an hour. In the step three, the stirring is at 300 r / min magnetic force for 15 min.

[0014] Further, in the step five, the heating temperature is 60℃, and the heating time is 1 hour.

[0015] The application also relates to a self-packaged stretchable electrode prepared by any of the self-packaged stretchable electrode preparation methods.

[0016] Beneficial effects

[0017] The self-packaged stretchable electrode and the preparation method thereof have the following prominent features and excellent effects compared with the prior art:

[0018] The application can omit the packaging process of the existing electrode to form a self-packaged printing electrode. The surfactant Triton X-100 is used to uniformly mix the oily packaging material such as Ecoflex and the aqueous dispersion liquid of PEDOT:PSS, and the initial line width of the electrode can be controlled by means such as electrofluid jet printing. Due to the metastability of the solution, Ecoflex gradually diffuses to the surrounding, the stability of the uniformly dispersed solution is gradually destroyed, and two-phase separation occurs again. The incompatibility between the aqueous dispersion liquid of PEDOT:PSS and Ecoflex restricts the diffusion of PEDOT:PSS, maintains or reduces the pattern line width of the electrode layer, and the conductivity of the conductive layer is enhanced due to the aggregation of PEDOT:PSS. After about 30 min, the PEDOT:PSS and Ecoflex are completely separated. After Ecoflex is heated at 60℃ for one hour, the A-phase and B-phase Ecoflex are completely solidified to form an electrode protection layer.

[0019] The application can prepare a flexible stretchable electrode capable of self-packaging, innovates the electrode assembly process, solves the problems of high economic and time cost of the multi-layer packaging process, and further refines the electrode line width and improves the electrode stability when the electrode changes from a composite state to a separated state, and the electrode pattern is easy to be refined. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The conductive ink preparation flowchart in the application.

[0021] Figure 2 The printing effect diagram of the application on the PET substrate.

[0022] Figure 3 The printing electrode line width schematic diagram in the application.

[0023] Figure 4 The electrode test effect diagram in the present application (left is the stretchable electrode of the present application, and right is the PEDOT:PSS non-encapsulated printed electrode).

[0024] Figure 5 The electrode stretch effect diagram of the PEDOT:PSS electrode with different concentrations in the present application under the gradient stretch of 0-20%. DETAILED DESCRIPTION

[0025] The following is combined Figures 1 to 5 The present embodiment is specifically described. The specific method steps of the present application are as follows:

[0026] Step one, add an oily encapsulating material and a non-ionic surfactant to the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) aqueous dispersion solution; the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) aqueous dispersion solution accounts for 30%-40% of the total mass of the solution. The non-ionic surfactant accounts for 2%-2.5% of the total mass of the solution. The non-ionic surfactant is Triton X-100, polysorbate 20 or Igepal CA-630.

[0027] Step two, stir the solution obtained in step one, and the stirring is magnetic stirring at 300 r / min for half an hour to obtain a uniformly dispersed poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and oily encapsulating material blended solution.

[0028] Step three, add a curing encapsulating material corresponding to the oily encapsulating material to the blended solution of step two, and after stirring, a printing ink is obtained; the stirring is magnetic stirring at 300 r / min for 15 min.

[0029] The oily encapsulating material is Ecoflex A silicone, Ecoflex B silicone or polydimethylsiloxane (PDMS); in step three, the curing encapsulating material is Ecoflex B silicone, Ecoflex A silicone or a platinum catalytic curing agent. The curing encapsulating material corresponding to the oily encapsulating material is different in each operation.

[0030] Step four, print the electrode by electrohydrodynamic jet printing, and after standing, two phases are separated to form an electrode layer and an encapsulating layer.

[0031] Step five, after heating the obtained electrode in an oven at 40-80℃ for 0.5-2 hours, a self-encapsulated stretchable electrode is obtained.

[0032] In summary, the present application is a self-separable and self-packaged electrode ink preparation realized by poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) aqueous dispersion and oily packaging material Ecoflex, under the action of surfactant Triton X-100. The self-packaged electrode ink preparation process is shown in the accompanying Figure 1 The self-packaged stretchable electrode is prepared by ink printing.

[0033] In the present application, Ecoflex A and Ecoflex B are both oily packaging materials, and the mixture of the two forms a stable packaging layer after curing. There is no order requirement for the addition of the two materials, and they can be replaced with each other. The present application needs to first form the blended solution of step two, which can be stored for a long time. When printing is needed, the operation of step three is started, Ecoflex B is added to form the printing ink.

[0034] Polydimethylsiloxane is another oily packaging material, which can be quickly cured to form a stable packaging layer after adding a small amount of curing agent (catalyst).

[0035] Ecoflex A and Ecoflex B are silicone materials that can be directly purchased. The Ecoflex used in the present application is purchased from Shanghai Zixin Technology Co., Ltd.

[0036] Example one

[0037] Step one: 0.7g Ecoflex A and 0.05g surfactant Triton X-100 are added to 0.6g PEDOT:PSS aqueous dispersion.

[0038] Step two: the solution obtained in step one is magnetically stirred at 300r / min for half an hour to obtain a uniformly dispersed PEDOT:PSS / Ecoflex A blended solution.

[0039] Step three: 0.7g Ecoflex B is added to the solution obtained in step two, and magnetically stirred at 300r / min for 15min to obtain a printing ink.

[0040] Step four: a 210um inner diameter needle is selected, and the electrode is printed by electrofluidic jet printing. After standing for half an hour, two phases are separated to form an electrode layer and a packaging layer.

[0041] Step five: the obtained electrode is heated in a 60℃ oven for 1 hour to prepare a stretchable electrode.

[0042] The separation effect after printing is good, and the printing effect on the PET substrate is shown in Figure 2

[0043] Example two

[0044] ​Step one, add 0.65g Ecoflex B and 0.04g surfactant polysorbate 20 into 0.7g PEDOT:PSS aqueous dispersion.

[0045] Step two, after the solution obtained in step one is magnetically stirred at 200r / min for 1 hour, a uniformly dispersed PEDOT:PSS / Ecoflex A blended solution is obtained.

[0046] Step three, after the solution obtained in step two is added with 0.65g Ecoflex A and magnetically stirred at 200r / min for 20 minutes, a printing ink is obtained.

[0047] Step four, select a 160um inner diameter needle, print the electrode by electrohydrodynamic jet printing, and after standing for half an hour, the two phases separate to form an electrode layer and an encapsulation layer.

[0048] Step five, after the obtained electrode is heated in a 40℃ oven for 2 hours, a stretchable electrode is prepared.

[0049] Example three

[0050] Step one, add 0.6g Ecoflex A and 0.045g surfactant Igepal CA-630 into 0.8g PEDOT:PSS aqueous dispersion.

[0051] Step two, after the solution obtained in step one is magnetically stirred at 350r / min for 20 minutes, a uniformly dispersed PEDOT:PSS / Ecoflex A blended solution is obtained.

[0052] Step three, after the solution obtained in step two is added with 0.6g Ecoflex B and magnetically stirred at 350r / min for 15 minutes, a printing ink is obtained.

[0053] Step four, select a 260um inner diameter needle, print the electrode by electrohydrodynamic jet printing, and after standing for half an hour, the two phases separate to form an electrode layer and an encapsulation layer.

[0054] Step five, after the obtained electrode is heated in an 80℃ oven for half an hour, a stretchable electrode is prepared.

[0055] Separation effect and stability test

[0056] After the electrode printed using a 210um inner diameter needle is left to stand for half an hour, the two phases separate, and under an optical microscope, the encapsulation layer line width is 421um, and the PEDOT:PSS conductive layer line width is 192um, indicating that the separation effect is good, and the oily encapsulation Ecoflex limits the diffusion of PEDOT:PSS, keeping the line width stable, as shown in Figure 3

[0057] ​Stretchability test

[0058] The printed electrode of the present application and the printed PEDOT:PSS encapsulated electrode are stretched with a gradient of 4% to a gradient of 0-20%, the electrode resistance increases with the increase of the stretching amount, the pure PEDOT:PSS has a fluctuation increase in resistance after 12% stretching, and is not suitable for use as a stretchable electrode. The printed electrode of the present application can still maintain good stability at 20%, and the electrode resistance remains unchanged after repeated stretching of 0-20% at 20% stretching, and can realize the function of a stretchable electrode, as shown in Figure 4 .

[0059] Adjusting the content of PEDOT:PSS in the electrode of the present application to 30%-40%, the higher the content of PEDOT:PSS, the smaller the initial resistance, and the greater the change in relative resistance after stretching, the resistance is the smallest after 20% stretching of 40% PEDOT:PSS, and the ink is more water-soluble above 40%, which is not conducive to printing, and the encapsulation layer is too thick below 30%, the test resistance fluctuates greatly, and is not suitable for use as an electrode, as shown in Figure 5 .

[0060] The above description of the present application is only the preferred embodiments of the present application, and is not used to limit the embodiments of the present application, and those skilled in the art can easily make corresponding changes or modifications according to the main concept and spirit of the present application, therefore the protection scope of the present application should be subject to the protection scope required by the claims.

Claims

1. A method for fabricating a self-encapsulated stretchable electrode, characterized in that, The method comprises the following steps: Step one, adding an oily encapsulating material and a non-ionic surfactant into a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous dispersion solution; Step two, stirring the solution obtained in step one to obtain a uniformly dispersed poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and oily encapsulating material blended solution; Step three, adding a solidified encapsulating material into the blended solution of step two, and stirring to obtain a printing ink; Step four, printing an electrode by electrohydrodynamic jet printing, and allowing the two phases to separate after standing to form an electrode layer and an encapsulating layer; Step five, heating the obtained electrode to obtain a self-encapsulated stretchable electrode; In step one, the oily encapsulating material is Ecoflex A silicone, Ecoflex B silicone or polydimethylsiloxane; In step three, the solidified encapsulating material is Ecoflex A silicone, Ecoflex B silicone or a platinum catalyzed curing agent; In step three, the solidified encapsulating material is different from the oily encapsulating material; In step one, the non-ionic surfactant is Triton X-100, polysorbate 20 or Igepal CA-630.

2. The method of claim 1, wherein the self-packaged stretchable electrode is prepared by, In step one, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous dispersion solution accounts for 30%-40% of the total mass of the solution.

3. The method of claim 1, wherein the self-packaged stretchable electrode is prepared by, In step one, the non-ionic surfactant accounts for 2%-2.5% of the total mass of the solution.

4. The method of claim 1, wherein the self-packaged stretchable electrode is prepared by, In step two, the stirring is magnetic stirring at 200-350 r / min for 0.5 hours; in step three, the stirring is magnetic stirring at 200-350 r / min for 15-20 min.

5. The method of claim 1, wherein the self-packaged stretchable electrode is prepared by a process comprising: In step four, the inner diameter needle for electrohydrodynamic jet printing is 210-260 um; in step five, the heating temperature is 40-80℃, and the heating time is 0.5-2 hours.

6. A self-encapsulated stretchable electrode prepared by the method of any one of claims 1 to 5.

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