Developing Stretchable Multicolor Mechanoluminescent Composites with High Flexibility and Durability

Description

Mechanoluminescence (ML) materials recently have shown great promise for applications in stress visualization, lighting, and optical signaling. However, current trigger modes of ML need either destructive action (fracture) or high mechanic load (up to order of 10^3 N). The rising demands for flexible device with stress sensing and colour display characteristics have brought up attentions on ML materials which are capable of emitting light in an elastomeric framework, such as polydimethylsiloxane (PDMS). The existing elastomer-based ML composites mainly employ transition metal doped sulfides as luminescent component, which limits the range of available ML colors. Here, we propose to develop a series of elastomer composites containing lanthanide ions (Ln3+) doped semiconductor compounds for performing mechanically activated multicolor light emission. The diverse 4f-4f electronic transitions of Ln3+ endow a library of emitting spectra spanning ultraviolet to near infrared. Al2O3 layer will be coated on the microcrystal surface to assist effective stress transfer from matrix to the doped crystal by virtue of intimate adhesion between Al2O3 and siloxane matrix. Moreover, we intend to investigate the detailed physical origins of ML through experimental investigation and theoretical prediction. These crystals with carefully designed composition and microstructure may inspire new research interests in ML field and fascinate researchers from different application areas.