[TuA4] Organic Devices

6:15 PM - 6:30 PM JST(9:15 AM - 9:30 AM UTC)

[TuA4-06] Room-temperature Gold Bonding on Nanomesh

〇Yusuke Ebihara¹, Masahito Takakuwa¹, Kento Yamagishi², Tomoyuki Yokoya¹, Takao Someya¹ (1. The University of Tokyo (Japan), 2. Tokyo University of Agriculture and Technology (Japan))

With the advancement of flexible electronics and wearable devices, there is a growing demand for bonding technologies with low stiffness and high conductivity suitable for thin-film electronic devices. In particular, nanomesh substrates consisting of nanofibers (~1 µm) are expected to be applied to skin-attachable sensors and electrodes due to their high breathability and flexibility. However, conventional bonding using conductive adhesives has made it difficult to achieve stable connections while maintaining flexibility and breathability.In this study, we propose a direct gold bonding technology on nanomesh that can be realized under room temperature and low-pressure conditions without the need for surface activation treatment. Polyurethane nanofiber sheets were fabricated using the electrospinning method, followed by the formation of a gold thin film. By pressing these samples together at a pressure of ~1 MPa, room-temperature direct gold bonding was achieved. The electrical resistance of the bonding was sufficiently small compared to the nanomesh itself, and no significant change in resistance was observed even after 10,000 cycles of repeated bending tests. These results indicate that a stable direct gold bond is formed on the nanomesh substrate. This method is promising for the packaging technology of next-generation flexible devices, including on-skin electronics.