CN115980131A

CN115980131A - Planar mechanical controllable junction cracking technology based on flexible material

Info

Publication number: CN115980131A
Application number: CN202211311292.1A
Authority: CN
Inventors: 赵雪妍; 向东; 谭敏; 张素荣; 张旭斌; 许晓娜
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2023-04-18
Anticipated expiration: 2042-10-25
Also published as: CN115980131B

Abstract

The chip manufactured based on the flexible thin film material utilizes the mechanical force in the vertical direction generated by the piezoelectric ceramics, stretches the flexible substrate in the horizontal direction in a mode of combining a slide rail and the piezoelectric ceramics, drives the micro structure on the substrate to stretch or shrink, realizes the formation and the fracture of the metal junction constructed in the horizontal direction, has simple operation and low cost, overcomes the difficulty of light beam focusing in the external light field, is beneficial to obtaining the monomolecular junction, and researches the monomolecular characteristics.

Description

Planar mechanical controllable junction cracking technology based on flexible material

Technical Field

The invention is applied to mechanical controllable junction cracking technical devices, is particularly realized based on flexible materials, and relates to the fields of molecular electronics, flexible materials, optics and the like.

Background

Semiconductor silicon-based devices have been widely used in various fields, and in 1965, it was suggested that the size of electronic components will exponentially shrink with time, and when the conventional silicon-based semiconductor devices cannot meet the demand for size reduction, molecular electronics has come to mind, and the functions of electronic devices are realized by using the properties of atoms, molecules or molecular clusters. More importantly, as the molecular device is usually in the scale range smaller than 10nm, the transport property of the molecular device is more obviously influenced by various quantum effects, so that the molecular device shows many different working principles and device performances from the traditional device, and further promotes the development of molecular electronics. The method for constructing the functional photoelectronic device by utilizing the single molecule not only can meet the requirements of miniaturization and high integration of the device, but also can research the intrinsic physical and chemical phenomena and the regulation and control rule of the material on the molecular level, and is the scientific basis for the development of the molecular photoelectronic device in the future. The realization of field effect transistors has led to a rapid advance in the development of molecular electronics, and single-molecule Junction technology has also been rapidly developed, and the approaches are more diversified, wherein the widely used method mainly includes a mechanical Controllable crack Junction (MCBJ) technology and a Scanning Tunneling Microscope crack Junction (STM-BJ) method.

The STM uses ductility of noble metals to prepare an electrode-molecule-electrode junction by stretching and shrinking in a vertical direction. This has limited the research of the photoelectric characteristic of molecular device, though can reform transform on STM's basis, for example build the light path on optical platform, with light irradiation to the basement electrode on, the mode of this kind of plus light field is comparatively complicated, and the light path is difficult for removing after fixing, is unfavorable for subsequent operation. For the mechanical controllable nano-junction cracking technology, the device consists of a flexible substrate and a gold wire with a notch, and when the substrate is bent upwards, the metal wire is precisely controlled to be cracked through a piezoelectric element to form an electrode. Although the stability is high, the light spot is difficult to focus when moving in the vertical direction due to the influence of the cracking mode, and the research on the photoelectric property of the molecule is limited. Based on this, it is very important to provide a simple and highly repeatable plane-splitting junction technique capable of realizing single-molecule measurement at room temperature.

TPU (Thermoplastic polyurethanes), thermoplastic polyurethane elastomer rubber, have excellent high tension, high tensile force, toughness and ageing-resistant characteristics, have been widely applied to various aspects such as electronics, medical treatment, sports and the like at present, and compared with other elastic materials, have incomparable high strength and ageing-resistant characteristics. A TPU flexible material of a specified thickness can be used as a substrate instead of a spring steel sheet on which metal electrodes are fabricated.

The invention utilizes TPU flexible material as a substrate, utilizes the tensile force generated by piezoelectric ceramics to stretch the TPU flexible film, drives the metal wire to move, and realizes the process of plane metal atomic-level fracture. And when an optical field is added, the problem of focal length change in the traditional split junction technology can be avoided, and a new technical means is provided for the research of the monomolecular photoelectric effect.

Disclosure of Invention

The invention aims to provide a method for realizing controllable junction splitting in the horizontal direction by taking a flexible material as a substrate and utilizing piezoelectric ceramics to drive a flexible film to stretch based on the limitation brought by the research on the single-molecule photoelectric effect in the existing junction splitting technology.

The invention comprises a substrate with holes, a TPU flexible chip, piezoelectric ceramics, a straight guide rail, a slide bar and a current equipment analyzer. Wherein the TPU flexible chip comprises the following components: and the gold thread with the suspended groove in the middle part is fixed on the TPU flexible film through black glue.

The method comprises the following specific steps: the flexible chip is arranged on a substrate with a hole, and is fixed in a three-section fixing mode, namely two ends fixed on the substrate and one end connected to the sliding rod. One end of the chip fixed on the substrate is tightly fixed on the substrate through the brass pressing sheet, and the other end of the chip is also fixed on the substrate through the brass pressing sheet but is not completely fixed, so that a certain gap is reserved between the chip and the substrate, the purpose of the method is to enable the part with the gold threads to be in close contact with the substrate as far as possible, and the brass sheet which is not completely pressed and fixed provides possibility for stretching of the flexible film, and the horizontal stretching direction is fixed; connecting the rest part of the flexible film with the slide bar of the straight guide rail, wherein the tail end of the slide bar is arranged on the ejector rod of the piezoelectric ceramics, the ejector rod at the top of the piezoelectric ceramics can just penetrate out of the hole of the substrate, and the piezoelectric ceramics can drive the slide bar to move when displacement occurs, so that the flexible substrate can be stretched, and finally, the stretching and shrinking of the metal structure in the horizontal direction can be realized; the metal wire on the chip is connected with an external current equipment analyzer through two wires to control the movement of the piezoelectric ceramics and measure the electrical signals of the piezoelectric ceramics.

The invention has the technical advantages that: the method has the advantages of simple operation, low cost, overcoming the difficulty of light beam focusing when an optical field is applied, high experimental repeatability and certain universality.

Drawings

In order to make the purpose and technical solution of the present invention clearer, the present invention will be further described in detail with reference to the accompanying drawings:

fig. 1 is a schematic view of a planar mechanical controlled split junction device based on a flexible material.

Fig. 2 is a schematic diagram of a chip part made of a flexible material substrate.

Fig. 3 is an enlarged view of a key part of a chip made of a flexible material substrate.

Fig. 4 shows that when the piezoelectric moves upwards, the conductance value of the gold atomic junction decreases along with the stretching of the flexible substrate until disconnection.

Fig. 5 shows that when the piezoelectric moves upwards, the conductance value of the silver atomic junction is reduced along with the stretching of the flexible substrate until the flexible substrate is disconnected.

In the figure: the device comprises a straight guide rail 1, a sliding rod 2, a piezoelectric ceramic ejector rod 3, piezoelectric ceramic 4, a substrate with holes 5, a flexible substrate 6, a brass pressing sheet 7 for pressing and fixing one end of a flexible film, a pressing sheet 8 for fixing the tail end of the flexible film and the sliding rod, a semi-fixed brass pressing sheet 9, a metal joint 10 and a circuit of a current equipment analyzer 11.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

Example (b): tailor suitably bigThe method comprises the following steps of taking a small TPU film (the length is about 500mm, the width is 150 mm) as a substrate, cutting a gold wire or a silver wire (the length is about 100mm, the diameter is 100um, and the purity is 99.99%) with a certain length, performing girdling on the middle part of the metal wire by using a scalpel to form a suspended metal groove (9), adhering the cut gold wire to a flexible film by using black glue (epoxy resin, STYCAST 2850 FT), and manufacturing a chip to be tested. The chip is placed on a planar mechanical controllable junction cracking technical device, a flexible chip (6) placed on a substrate (5) is fixed through two pressing sheets (7) and (9), the rest flexible film part is fixed with a sliding rod through a pressing sheet (8), when a bottom piezoelectric device (4) moves up and down in the vertical direction, a push rod (3) on the piezoelectric drives a sliding rod (2) connected to a straight guide rail (1) to move in the vertical direction, the flexible film (6) is stretched to enable the flexible film (6) to move transversely, fixed bias voltage 100mV (11) is applied to two ends of a metal junction, and measurement of dynamic electrical signals in the stretching and compressing processes of the metal junction is achieved. When the piezoelectric ceramic moves upwards, the transverse stretching of the flexible chip is driven, the metal junction is gradually stretched, and the integral multiple G can be gradually observed ₀ (G ₀ Single atomic junction conductance) until final fracture.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover equivalent methods within the spirit and scope of the appended claims.

Claims

1. A planar mechanical controllable crack technology based on flexible materials is characterized in that: the flexible material is used as a substrate, and the metal atomic level fracture is realized in the horizontal direction. The device comprises a substrate with holes, piezoelectric ceramics, a thermoplastic polyurethane elastomer rubber (TPU) flexible chip (comprising a strip-shaped flexible film and a gold wire fixed above the strip-shaped flexible film), a straight guide rail and a slide bar, wherein the piezoelectric ceramics are arranged on the substrate; the substrate is a rectangular substrate with holes, the flexible chip is fixed on the substrate and integrally fixed on the support of the piezoelectric ceramics, so that the support fixed on the piezoelectric ceramics can just penetrate out of the holes of the substrate; the flexible chip is fixed in a sectional fixing mode, namely one end fixed on the substrate and one end connected to the sliding rod are respectively fixed, one end of the flexible chip fixed on the substrate is tightly fixed on the substrate through the brass pressing sheet, the other end of the flexible chip is fixed on the substrate through the brass pressing sheet, but the flexible chip is not completely fixed, a certain gap is reserved between the film and the pressing sheet, the flexible film of the flexible chip can freely move in the horizontal direction, the rest part of the flexible film is connected with the sliding rod of the straight guide rail, the tail end of the sliding rod is arranged on the piezoelectric ceramic support, and when the piezoelectric ceramic moves up and down, the sliding rod can be driven to move in the vertical direction, so that the flexible substrate generates elastic deformation in the horizontal direction. And fixing the gold wire with the notch in the middle above the film by using black glue (epoxy resin). Horizontal stretching of the flexible film can result in the breaking of the gold wires secured thereover, while shrinking of the film can result in the reattachment of the gold wires.

2. The method of claim 1, wherein the flexible substrate is subjected to planar mechanical controlled cracking, and wherein: the flexible material is a stretchable TPU film.

3. The method of claim 1, wherein the flexible substrate is subjected to planar mechanical controlled cracking, and wherein: the flexible material is fixed on the substrate, one end of the substrate is completely fixed by the copper sheet, a certain gap is reserved when the other end of the substrate is fixed by the method, the flexible film is conveniently stretched, and the rest part of the flexible film is fixed on the sliding rod.

4. The method of claim 1, wherein the flexible substrate is subjected to planar mechanical controlled cracking, and wherein: the piezoelectric ceramics are used as supports and are used together with a straight guide rail with a slide bar, so that the slide bar moves up and down along with the piezoelectric ceramics.

5. A method of planar mechanical controlled cleaving of a flexible substrate as claimed in claims 1 and 3, wherein: one end of the flexible chip of the substrate is tightly fixed, and the other end of the flexible chip is semi-fixed, and meanwhile, the remaining flexible film is connected and fixed with the sliding rod, so that the flexible chip is transversely stretched when the piezoelectric ceramic reciprocates up and down.

6. The method of claim 1, wherein the flexible substrate is a planar mechanical controlled split junction comprising: the flexible film is displaced when stretched, so that the metal electrode on the film is driven to move and the gold wire is stretched, and the atomic-level fracture process is realized.

7. The method of claim 1, wherein the flexible substrate is subjected to planar mechanical controlled cracking, and wherein: the flexible material is not limited to the use of TPU material, other flexible films may implement the fracture process at the atomic level.

8. The method of claim 1, wherein the flexible substrate is subjected to planar mechanical controlled cracking, and wherein: the fracture process is observed at the atomic level using either gold or silver as the electrode material.