A method for preparing a zero-piezoresistance stretchable flexible electronic device

Abstract

The present invention discloses a method for preparing a zero-piezoresistance stretchable flexible electronic device, which comprises the following steps: firstly designing a pattern of a conductive module unit on a temporary carrier, obtaining an area where the conductive module unit needs to be grown after exposure and development, then patterning the growth site of a nano material on the surface of the temporary carrier, and then growing vertical gold nanowires on the designed conductive module unit pattern after the photoresist on the surface of the temporary carrier is washed away, and then domino-like conductive module units are directed and orderly assembled through capillary force, and the conductive module units partially overlap after collapse to form a conductive network, and the orderly collapsed conductive domino network is transferred to a stretchable substrate to form a micro-nano structure that can maintain a stable resistivity when stretched by an external force, thereby preparing a zero-piezoresistance flexible electronic sensor and solving the signal interference problem caused by resistivity changes of the stretchable flexible electronic device when stretched by an external force.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, and in particular to a method for preparing a zero-piezoresistance stretchable flexible electronic device. Background Art

[0002] At present, stretchable flexible electronic devices, as an important part of flexible electronic devices, are being widely used in medical health and wearable smart devices. Traditional stretchable flexible electronic devices based on the piezoresistive effect mostly exhibit positive piezoresistive coefficient, that is, the resistivity increases with the increase of tension or deformation. However, in recent years, new application scenarios have emerged that require stretchable flexible electronic devices to maintain a stable resistivity under positive deformation conditions, that is, zero piezoresistive coefficient sensors. For example, stretchable interconnects for signal transmission, or tension-insensitive sensors, need to strictly control their resistance changes within the deformation range within 5% to avoid excessive resistance disturbances causing circuit instability, generating signal bias, reducing the signal-to-noise ratio, and exceeding the processor's acceptance range. Therefore, previous stretchable flexible electronic devices have failed to meet these requirements well. Therefore, it is now necessary to make zero piezoresistive coefficient stretchable flexible electronic devices to meet new application needs. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a zero-piezoresistance stretchable flexible electronic device, thereby solving the problem of signal interference caused by resistivity changes when the stretchable flexible electronic device is stretched by external force.

[0004] A method for preparing a zero-piezoresistance stretchable flexible electronic device comprises the following steps:

[0005] 1. Setting a number of equally spaced gold nanowire growth sites on a temporary carrier, growing gold nanowires on the growth sites to form a gold nanowire domino module unit;

[0006] Second, the gold nanowire domino module units are oriented and sequentially collapsed in the form of dominoes on a temporary carrier, so as to overlap each other to form a conductive network;

[0007] 3. Transfer the conductive network to a stretchable substrate, and set fixed electrode sheets near both ends of the stretchable substrate to connect the two ends of the conductive network respectively.

[0008] As a preferred embodiment of the present invention, in the step one, a photoresist is spin-coated on a temporary carrier, and a number of equidistantly arranged conductive module unit areas are etched in the photoresist through exposure and development, and a gold seed is set on the temporary carrier in each conductive module unit area to form a gold nanowire growth site, and then the remaining photoresist on the temporary carrier is washed away, and the gold seeds are used as catalysts to immerse in a nano-gold growth solution to grow vertical gold nanowire domino module units.

[0009] As a preferred embodiment of the present invention, in step 2, the temporary carrier together with the gold nanowire domino module units are immersed in a mixed solution of ethanol and water, left to stand for a period of time and then taken out and dried, and the gold nanowire domino module units are assembled in a directional sequence by using capillary force or directional wind blowing to form a conductive network that collapses in sequence and overlaps each other.

[0010] As a preferred embodiment of the present invention, the gold nanowire domino module unit 31 is rectangular, with a width of 1-10 μm, a length of 10-1000 μm, a height of 1-100 μm, and a distance between every two gold nanowire domino module units 31 of 1-30 μm.

[0011] As a preferred embodiment of the present invention, in step three, the conductive network is transferred to the stretchable substrate 5 by releasing by tape transfer or by dissolving after adhesion transfer of a water-soluble polymer film.

[0012] As a preferred embodiment of the present invention, the stretchable substrate is SEBS, TPU or PDMS.

[0013] As a preferred solution of the present invention, the temporary carrier is glass, silicon or ceramic.

[0014] Compared with the prior art, the method for preparing a zero-piezoresistance stretchable flexible electronic device in an embodiment of the present invention has the following beneficial effects: first, a pattern of a conductive module unit is designed on a temporary carrier, and an area where the conductive module unit needs to be grown is obtained after exposure and development, and then the growth site of the nanomaterial is patterned on the surface of the temporary carrier, and after the photoresist on the surface of the temporary carrier is washed off, vertical gold nanowires can be grown on the designed conductive module unit pattern, and then the domino-like conductive module units are directed and orderly assembled through capillary force, and the conductive module units partially overlap after collapse to form a conductive network, and the orderly collapsed conductive domino network is transferred to a stretchable substrate to form a micro-nano structure that can maintain a stable resistivity when stretched by an external force, thereby preparing a zero-piezoresistance flexible electronic sensor, solving the signal interference problem caused by the resistivity change of the stretchable flexible electronic device when stretched by an external force, and can be applied in scenarios with strict requirements on signal stability to reduce signal interference and improve the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a side view of a structure for spin coating photoresist on a temporary carrier in an embodiment of the present invention;

[0016] Figure 2 is a structural diagram of a conductive module unit region disposed in a photoresist in an embodiment of the present invention;

[0017] Figure 3is a side view of a structure in which a conductive module unit region is arranged in a photoresist in an embodiment of the present invention;

[0018] Figure 4 is a top view of a structure in which a gold seed is arranged on a temporary carrier and the photoresist is washed away in an embodiment of the present invention;

[0019] Figure 5 It is a top view of the structure of a gold nanowire domino module unit grown vertically by immersing in a nano-gold growth solution in an embodiment of the present invention;

[0020] Figure 6 This is a structural side view of a gold nanowire domino module unit immersed in a nano-gold growth solution and grown vertically in an embodiment of the present invention;

[0021] Figure 7 is a structural side view of a sequentially collapsed gold nanowire domino module unit in an embodiment of the present invention;

[0022] Figure 8 is a side view of a structure in which a conductive network is transferred to a stretchable substrate in an embodiment of the present invention;

[0023] Fig. 9 is a top view of a structure in which a fixed electrode sheet is provided in an embodiment of the present invention;

[0024] Fig.10 It is a side view of a structure in which a fixed electrode sheet is arranged in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0026] In the description of the present invention, it should be understood that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the description of the present invention, it is also necessary to understand that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the machine or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be understood that when the terms "first", "second", etc. are used in the present invention to describe various information, such information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the "first" information may also be referred to as the "second" information, and similarly, the "second" information may also be referred to as the "first" information.

[0028] refer to Figure 1 -10. A method for preparing a zero-piezoresistance stretchable flexible electronic device according to an embodiment of the present invention comprises the following steps:

[0029] 1. Setting a plurality of independent gold nanowire growth sites arranged equidistantly on the temporary carrier 1, and growing gold nanowires on the growth sites to form a gold nanowire domino module unit 31;

[0030] 2. On the temporary carrier 1, the gold nanowire domino module units 31 are sequentially collapsed in a domino-like manner, so as to overlap each other to form a conductive network 4;

[0031] 3. The conductive network 4 is transferred to the stretchable substrate 5, and fixed electrode sheets 6 are arranged near the two ends of the stretchable substrate 5 to connect the two ends of the conductive network 4 respectively. The power can be easily applied by connecting the wires through the fixed electrode sheets 6. After the stretchable substrate 5 is stretched by external force, the adjacent conductive module units produce sliding displacement but still overlap each other, and show only a 10% resistance change rate under 100% strain. The resistance change is insensitive to strain, showing a zero piezoresistance effect. This electronic device can be stretched and can fit the skin to be made into an electronic sensor device similar to human skin. This zero piezoresistance coefficient stretchable flexible electronic device can be used in scenarios with strict requirements on signal stability to reduce signal interference and improve the signal-to-noise ratio.

[0032] refer to Figure 1 -6. Exemplarily, in the step one, a photoresist 2 is spin-coated on a temporary carrier 1, and the shapes and areas of several equidistantly arranged conductive module unit regions 21 are etched in the photoresist 2 by exposure and development, and a gold seed 3 is set on the temporary carrier 1 in each conductive module unit region 21 to form a gold nanowire growth site, and then the remaining photoresist 2 on the temporary carrier 1 is washed away, and the gold seed 3 is used as a catalyst to immerse in a nanogold growth solution to grow vertical gold nanowire domino module units 31.

[0033] refer to Figure 7 For example, in step 2, the temporary carrier 1 together with the gold nanowire domino module unit 31 is immersed in a mixed solution of ethanol and water, and after standing for a period of time, it is taken out and dried, and the gold nanowire domino module unit 31 is assembled in a directional sequence by using capillary force or directional wind blowing to form a conductive network 4 that collapses in sequence and overlaps each other.

[0034] refer to Figure 1 For example, the gold nanowire domino module unit 31 is rectangular, with a width of 1-10 μm, a length of 10-1000 μm, and a height of 1-100 μm. The distance between each two independent gold nanowire domino module units 31 is 1-30 μm.

[0035] refer to Figure 1 For example, in step three, the conductive network 4 is transferred to the stretchable substrate 5 by releasing by tape transfer or by dissolving after transferring by adhesion of a water-soluble polymer film.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a zero-piezoresistance stretchable flexible electronic device, characterized in that The following steps are involved:

1. Setting a number of equally spaced gold nanowire growth sites on a temporary carrier, growing gold nanowires on the growth sites to form a gold nanowire domino module unit; Second, the gold nanowire domino module units are oriented and sequentially collapsed in the form of dominoes on a temporary carrier, so as to overlap each other to form a conductive network; 3. transferring the conductive network to a stretchable substrate, and setting fixed electrode sheets near both ends of the stretchable substrate to connect the two ends of the conductive network respectively; In the step 1, a photoresist is spin-coated on a temporary carrier, and a plurality of equidistantly arranged conductive module unit regions are etched in the photoresist by exposure and development, and a gold seed is set on the temporary carrier in each conductive module unit region to form a gold nanowire growth site, and then the remaining photoresist on the temporary carrier is washed away, and the gold seed is used as a catalyst to immerse the nano-gold growth solution to grow a vertical gold nanowire domino module unit; In step 2, the temporary carrier together with the gold nanowire domino module units are immersed in a mixed solution of ethanol and water, left to stand for a period of time and then taken out and dried, and the gold nanowire domino module units are assembled in a directional sequence by using capillary force or directional wind blowing to form a conductive network that collapses in sequence and overlaps each other.

2. The method for preparing a zero-piezoresistance stretchable flexible electronic device according to claim 1, characterized in that: The gold nanowire domino module unit is rectangular, with a width of 1-10 μm, a length of 10-1000 μm, a height of 1-100 μm, and a distance between every two gold nanowire domino module units of 1-30 μm.

3. The method for preparing a zero-piezoresistance stretchable flexible electronic device according to claim 1, characterized in that: In the step three, the conductive network is transferred to the stretchable substrate by releasing through tape transfer or by dissolving after adhesion transfer of a water-soluble polymer film.

4. The method for preparing a zero-piezoresistance stretchable flexible electronic device according to claim 1, characterized in that: The stretchable substrate is SEBS, TPU or PDMS.

5. The method for preparing a zero-piezoresistance stretchable flexible electronic device according to claim 1, characterized in that: The temporary carrier is glass, silicon or ceramic.

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