Flexible electronic devices are developing rapidly and are widely used in fields such as medical diagnosis, monitoring, and flexible robots. Flexible electronics cover organic electronics, plastic electronics, bioelectronics, nanoelectronics, printed electronics, etc., including multiple applications such as RFID, flexible displays, organic electroluminescent (OLED) displays and lighting, chemical and biological sensors, flexible photovoltaics, flexible memory and storage, flexible batteries, and wearable devices. With their rapid development, the fields they involve have also expanded further, and they have now become one of the research hotspots in interdisciplinary sciences.

Science listed organic electronics technology as one of the top ten scientific and technological achievements in the world in 2000. American scientists Alan Heeger, Alan MacDiarmid, and Japanese scientist Hideki Shirakawa won the 2000 Nobel Prize in Chemistry for their pioneering work in the field of conductive polymer materials. In recent years, famous domestic universities such as Tsinghua University, Northwestern Polytechnical University, Nanjing University of Technology, and Huazhong University of Science and Technology have successively established specialized research institutions for flexible electronic technology. Flexible electronic technology has attracted great attention and emphasis from Chinese researchers, and the research in the field of flexible electronics is extremely hot, making the development of this field changing with each passing day and achieving rapid progress.

Recently, the research team led by Professor Peng Huisheng from Fudan University successfully integrated the preparation of display devices with the fabric weaving process and published related results such as multifunctional micro optoelectronic devices integrated at the interweaving points of polymer composite fibers in Nature.

The research team led by Professor Wu Hao from Huazhong University of Science and Technology, in collaboration with Researcher Li Zhuo from Fudan University, developed a high-performance flexible electronic skin based on negative Poisson's ratio metamaterial structures. The related outcome "Flexible Mechanical Metamaterials Enabled Electronic Skin for Real-time Detection of Unstable Grasping in Robotic Manipulation" was published in Advanced Functional Materials.

The research team led by Professor Yutian Zhu from Hangzhou Normal University developed a stretchable and transparent multi - state electronic skin sensor composed of polyvinyl alcohol (PVA), citric acid (CA), and silver nanoparticles (AgNPs) through simple in-situ reduction and solution casting technology. It has multiple sensing capabilities in terms of strain, temperature, and humidity.

In the research process of flexible materials (flexible glass, flexible OLED, flexible batteries, flexible electronic skin) and flexible electronic components, the mechanical properties (yield strength, elongation, Poisson's ratio, Young's modulus) under a certain temperature environment are very important indicators for evaluating the application field quality of flexible materials and are also key process parameters for formulating flexible electronic manufacturing processes. Generally speaking, the load precision required for this test is relatively high, and the sample size is small. When testing mechanical properties such as yield, strength, and elongation, in the actual temperature heating/cooling environment, non-contact visual measurement instruments such as DIC are also needed for the tensile function at the same time.

In-situ Tensile Microscopic Stress - Strain Solution for Heating/Cooling Stage

The in-situ tensile microscopic stress - strain testing system for heating/cooling stages is mainly used in scientific research on various materials such as small - scale related flexible materials, biology, metals, organic polymers, and fibers. It can achieve a wide temperature range of - 190 - 600℃, a temperature control precision of ± 0.1℃, and a maximum load of 5kN. The in-situ tensile testing system for heating/cooling stages obtains data such as material deformation and temperature in real time under dynamic load, and combines DIC for material microstructure analysis data. It can quantitatively analyze the microscopic mechanical properties of materials, phase transformation behavior, orientation changes, crack initiation and propagation, material fatigue and fracture mechanisms, material bending, high - temperature creep, delamination, formation of slip bands, and peeling - off phenomena, so as to realize the research on the properties of various materials.

Three - dimensional digital image correlation technology (DIC) has the characteristics of accuracy, stability, and ease of use and has been widely used in strain measurement. However, for measurement samples that require high magnification, 3D measurement still has difficulty meeting the measurement requirements. This is mainly because 3D measurement lacks optical elements with sufficient depth of field and cannot obtain two high - magnification images required for 3D analysis from different perspectives. WTDIC - Micro makes up for the deficiency that traditional equipment cannot measure the deformation of small objects and becomes a powerful tool for deformation measurement in the microscopic scale field.

The testing system adopts a modular design. The core heating/cooling in-situ tensile stage is independently designed and manufactured using patented technology, and a heating/cooling in-situ microscopic stress testing system solution with high integration, multi - function compatibility, wide variable temperature range, flexibility and compactness, fast installation, simple operation, and reliable performance is developed, and it has a high cost - performance ratio.

1. Wide Application Range: It can be used for material science research in multiple disciplines such as metals, inorganic (semiconductors, ceramics), organic (biology, polymers, fibers), and composite coatings.

2. Strong Temperature Control Technology: Three variable temperature modules (semiconductor cooling/heating, liquid nitrogen/electric heating, etc.) can be freely replaced. The variable temperature range is - 190 - 600℃, RT - 1000℃, the temperature control precision is ± 0.1℃, and it has an independent intellectual property core temperature control algorithm.

3. Load Loading Function: Multiple special fixtures can be replaced to realize tensile, compression, and fatigue tests of test samples; the maximum tensile load is 5kN, the load precision is 0.2%; the tensile rate reaches 1 - 100 μm/s, and the maximum displacement is 50 mm.

4. Adaptability of Variable Temperature Tensile: It can be adapted to systems such as scanning electron microscopes, optical microscope systems, and X - ray diffractometers.

5. High Software Integration: It integrates temperature control and tensile testing, can set multiple parameters such as load, temperature, and displacement, and can perform complex cyclic load experiments in combination with flexible thresholds, and can conduct material research in real time as strain.

6. Rich Software Interface Performance: The system software provides multiple modes of material detection modes, temperature, load, and displacement threshold settings, curve generation, automatic data collection, and multiple format outputs.

7. Technical Support: Independent research and development, customized development and delivery; provide comprehensive solutions and technical guidance.

Three - dimensional Microscopic Strain Measurement System

WTDIC - Micro Microscopic Application Measurement System: The combination of an optical microscope and DIC digital image correlation technology can meet the measurement needs of sub - micron precision.

Usage Method Steps

In the testing process of small - size flexible samples, the usage method and steps of the in-situ tensile testing system for heating/cooling stages are as follows:

1. Make a speckle coating layer through a special small sample speckle spraying device. Of course, marking can also be done by methods such as line drawing, and video extensometers are all supported. However, after making the speckle coating layer, it can be extended to other uses, so we recommend processing it as a speckle coating layer. The completed sample is similar to the figure below.

Small - size Sample Speckle Effect

2.Place the small sample on the corresponding testing machine and clamp it.

Loading Sample into the In-situ Tensile Testing System for Heating/Cooling Stage

Test Results

1. Strain - State Curve

2.Displacement - State Curve

Temperature Fluctuation Curve

3.Data Table

Summary:

In the research of flexible materials, high - precision real - time acquisition of stress - strain data at different temperatures is an excellent solution to the problem of stress - strain measurement of flexible small - size samples in variable temperature environments. Jingtian Precision Instrument Technology (Suzhou) Co., Ltd. addresses the measurement difficulties in small - size sample mechanical tests and provides users with mature solutions, offering complete solutions in aspects such as the loading device, fixture design, and environmental control of small samples.