10.2.1.2　Dielectric materials

In e-skin devices which are based on transistors and capacitors，polymer dielectric materials are used as insulating layers，which require higher dielectric constant and lower leakage current.The PDMS described above is a commonly used polymer dielectric material.In the development of dielectric polymers，it was discovered that through the design of chemical structures（for example，the modification of polar groups such as cyano groups and fluorine atoms on the polymer chain），the addition of high-permittivity nanoparticles（e.g.，titanium dioxide，barium titanate）can increase the dielectric constant of polymer materials.While improving the dielectric properties，it is necessary to ensure the biocompatibility，flexibility and stretchability of the material.As the e-skin devices are usually in repeated stretching and bending，the durability and self-healing properties of dielectric materials are also important，which need to be paid attention during the device preparation.(https://www.daowen.com)