49-2:Invited Paper: Stretchable Passive Matrix LED Display with Thin-Film Based Interconnects

Abstract

In this contribution, a conformable 64x45 RGB light-emitting diode (LED) matrix is presented. A design concept of stretchable electronics is used: non-stretchable polymer islands host rigid LEDs and are interconnected by horseshoe shaped metallic conductors, which are able to deform together with an elastomeric substrate. Thin-film metallization is used to enable a pixel pitch of 1 mm, while polyimide is used to realize the non-stretchable islands, but also to support the meandering conductors. The design of the stretchable interconnections has been optimized with respect to their mechanical and electrical performance. Thermoplastic polyurethane is introduced at a final stage of the fabrication process to ensure its compatibility with conventional thin-film processing. A passive matrix addressing scheme is used to drive the LED matrix. At a supply voltage of 10 V, the brightness of the display reaches up to 700 cd/m 2 .

Percolating Network of Ultrathin Gold Nanowires and Silver Nanowires toward “Invisible” Wearable Sensors for Detecting Emotional Expression and Apexcardiogram

“…Flexible, bendable, and stretchable electronics have been explored for several decades and demonstrated a wide range of biomedical applications including cardiac impulse sensing, wrist pulses detecting, human motion monitoring, eye contact lenses, entertaining system like stretchable displays, and human‐machine interfaces . To build conformal contact with human skin/muscle with curvilinear surfaces, stretchable and bendable features are required—a capability impossible to achieve with existing rigid circuit board technologies which are for current‐generation rigid gadget‐based wearable products .…”

Laser‐Based Micro/Nano‐Processing Techniques for Microscale LEDs and Full‐Color Displays

“…Via holes are also important structures for interconnection of the various components between different layers for LED display applications. [94,95] For example, Verplancke et al [94] demonstrated a stretchable 64 × 45 RGB LED display prototype by assembling a RGB LED matrix onto the circuit using pick-and-place techniques, followed by interconnecting the anodes and cathodes between different layers through screen printing isotropic conductive adhesives into laser drilled via holes (Figure 6c). Phung et al used a similar strategy based on via holes to fabricate a LED matrix display on multilayer flexible printed circuit board.…”

“…[ 94,95 ] For example, Verplancke et al. [ 94 ] demonstrated a stretchable 64 × 45 RGB LED display prototype by assembling a RGB LED matrix onto the circuit using pick‐and‐place techniques, followed by interconnecting the anodes and cathodes between different layers through screen printing isotropic conductive adhesives into laser drilled via holes (Figure 6c). Phung et al.…”

“…c) A stretchable 64 × 45 RGB LED display prototype formed by interconnecting electrodes through screen printing isotropic conductive adhesives into laser drilled via holes. Reproduced with permission [94]. Copyright 2016, Society for Information Display, published by Wiley.…”

Ultrasensitive Strain Sensor Utilizing a AgF–AgNW Hybrid Nanocomposite for Breath Monitoring and Pulmonary Function Analysis

“…Highly sensitive, flexible, and stretchable nanocomposites with excellent electrical conductivity have been extensively investigated in recent years owing to their fascinating properties. These nanocomposites have been broadly used for applications ranging from wearable bioelectronics such as human motion monitoring − and pulse analyses − to modern electronics including flexible displays − and human–machine interfaces (HMIs). − To conformally attach the flexible electronics to curvilinear human skin, various properties such as bending, stretching, and adhesion are required to attain quality information about physiological health. While this is nearly impossible to achieve with current rigid electronic technologies, polymeric nanocomposite-based materials provide an attractive alternative and could fulfill the necessary requirements for wearable bioelectronic applications. , Among the possible applications to improve the quality of life, the need for wearable continuous respiratory monitoring is rapidly increasing due to the recent COVID-19 pandemic.…”