Research On The Enhancement Of Stretchability Of Flexible Devices Based On Microporous Structure

With its advantages of tiny size,light weight,strong carrier adaptability,etc.,flexible devices have a wide range of application in the fields of information,energy,medical treatment,national defense and so on.However,flexible devices still face many problems during testing,design and manufacturing:(1)In terms of testing,there is a lack of equipment specifically for the stretch testing of flexible devices,such as uniaxial stretch and circumferential stretch(2)In terms of design and manufacturing,the structure of substrate to ensure stable conductivity of flexible devices under the condition of large deformation is for further study.Based on the requirements of flexible devices for stretch testing equipment and reasonable substrate structure,this paper develops a stretch testing platform for flexible devices,reveals the mechanism of the blind-hole structure on the stretchability of flexible devices,and proposes a method for enhancing the stretchability of flexible devices based on a through-hole structure,And the above-mentioned stretch testing platform was used to verify the enhancement of stretchability of the flexible device based on the through-hole structure.The main research contents are as follows:1.In response to the requirements of flexible devices for uniaxial stretch and circumferential stretch tests,according to the idea of modular design,uniaxial stretch modules and circumferential stretch modules were designed to complete the mechanical system design of stretch testing platform;according to the control requirements of testing processes of the uniaxial stretch and circumferential stretch,the hardware circuit and PLC software system are designed,and the control system design of the stretch testing platform is completed;after online debugging,the stretch testing platform meets the requirements of uniaxial stretch and circumferential stretch tests of flexible devices.2.The uniaxial stretch simulation analysis of the PDMS film with blind-hole structure was carried out.The results showed that the strain around the blind hole showed a symmetrical distribution along the stretching direction and perpendicular to the stretching direction,and the strain along the stretching direction was far less than Strain perpendicular to the tensile direction.Such strain distribution causes the conductive layer on the PDMS film to generate regular cracks perpendicular to the stretching direction around the blind hole,and the blind hole can be used as a current bridge to maintain the conductivity of the electrode.3.The uniaxial stretch simulation analysis of the PDMS film with a through-hole structure is performed.The results show that it is feasible to use the through-hole structure to replace the blind-hole structure.The ratio of spacing to diameter is 0.1,which is the best for the enhancement of stretchability,and gradually decreases as the ratio deviates from 0.1.Under the limited processing conditions,through-hole PDMS thin-film electrodes and planar PDMS thin-film electrodes with a ratio of spacing to diameter of 0.5,1,2 were fabricated,and uniaxial stretch experiments were carried out,the results showed that the stretchability of the electrode on the through-hole PDMS film weakened with the increase of the spacing to diameter ratio,but it was enhanced compared to the electrode on the planar PDMS film.The electrode with the ratio of spacing to diameter of 0.5 has the best stretchability,can withstand up to 38% of the stretch deformation,which is 4 times higher than the electrode on the planar PDMS film.