Organic light-emitting diodes on shape memory polymer substrates for wearable electronics.

Green electrophosphorescent organic light-emitting diodes (OLEDs) with inverted top-emitting structures are demonstrated on bio-compatible shape memory polymer (SMP) substrates for wearable electronic applications. The combination of the unique properties of SMP substrates with the light-emitting properties of OLEDs pave to the way for new applications, including conformable smart skin devices, minimally invasive biomedical devices, and flexible lighting/display technologies. In this work, SMPs were designed to exhibit a considerable drop in modulus when a thermal stimulus is applied, allowing the devices to bend and conform to new shapes when its glass transition temperature is reached. These SMP substrates were synthesized using 1,3,5-triallyl-1,3,5-triazine-2,4,6(1 H ,3 H ,5 H )-trione (TATATO), trimethylolpropane tris(3-mercaptopropionate) (TMTMP), and tricyclo[5.2.1.0 2,6 ]decanedimethanol diacrylate (TCMDA), and show a low glass transition temperature of 43 °C, as measured using dynamic mechanical analysis (DMA). The OLEDs fabricated on these substrates exhibit high performance with a maximum efficacy of 33 cd/A measured at a luminance of 1000 cd/m 2 , and a peak luminance of over 30,000 cd/m 2 . [ABSTRACT FROM AUTHOR]