Nanomaterial-Based Macroscale Printable Flexible Sensors

Printable electronics are of great interests for flexible and wearable devices as next generation electronics. In fact, printable electrodes and transistors have been widely studied by using organic and inorganic materials on plastic substrates^1-3. To realize the practical, flexible device systems, many components such as transistors, sensors, and displays need to be integrated by using printing methods or compatible macroscale and low-cost fabrication methods.

   In this study, we propose printable sensor sheets using nanomaterial-based inorganic and organic solutions^4,5. Especially here printable strain and temperature sensors for different kinds of applications are demonstrated on flexible substrates such as silicone rubber, PET, etc. by using a screen printer and a laser patterning technique.  As a proof-of-concept, macroscale, low-cost sensor sheet in order to monitor the strain and cracking information from infrastructures and vehicles were fabricated on a silicone rubber using the screen printing method. The results exhibited that high sensitivity (~59%/Pa) strain sensor detected <10 µm displacement on a wall. This suggests that high sensitive low-cost sensor sheet can be used for the infrastructure monitoring system as an example.

   Furthermore, we will also talk about our recent results of a self-cleaning passivation layer for the flexible devices and more sensor applications such as an artificial electronic whiskers⁴ and smart bandage⁵.

   Our proposed printable flexible sensors may be applied to a variety of applications such as human interfaces, infrastructures, and vehicles.  

References:

1. Z. Fan et al., Advanced Materials, 21, 3730, 2009.
2. K. Takei et al., Nature Materials, 9, 821, 2010.
3. P. H. Lau et al., Nano Letters, 13, 3864, 2013.
4. S. Harada et al., ACS Nano, 2014 (DOI:10.1021/nn500845a).
5. W. Honda et al., Advanced Functional Materials, 2014 (DOI:10.1002/adfm.201303874)