Ultimate Control of Rate-Dependent Adhesion for Reversible Transfer Process via a Thin Elastomeric Layer.
Adhesion between a stamp with an elastomeric layer and various devices or substrates is crucial to successfully fabricate flexible electronics using a transfer process. Although various transfer processes using stamps with different adhesion strengths have been suggested, the controllable range of adhesion is still limited to a narrow range. To precisely transfer devices onto selected substrates, however, the difference in adhesion between the picking and placing processes should be large enough to achieve a high yield. Herein, we report a simple way to extend the controllable adhesion range of stamps, which can be achieved by adjusting the thickness of the elastomeric layer and the separation velocity. The adhesion strength increased with decreasing layer thickness on the stamp due to a magnification of the confinement and rate-dependent effects on the adhesion. This enabled the controllable range of the adhesion strength for a 15 μm-thick elastomeric layer to be extended up to 12 times that of the bulk under the same separation conditions. The strategy of designing stamps using simple adhesion tests is also introduced, and the reversible transfer of thin Si chips was successfully demonstrated. Tuning and optimizing the adhesion strength of a stamp according to the design process suggested here can be applied to various materials for the selective transfer and replacement of individual devices.
Department of Nano-Mechatronics, Korea University of Science & Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.|Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery & Materials (KIMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Chan
C
Kim
Department of Nano-Mechatronics, Korea University of Science & Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.|Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery & Materials (KIMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Min-Ah
MA
Yoon
Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery & Materials (KIMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Bongkyun
B
Jang
Department of Nano-Mechatronics, Korea University of Science & Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.|Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery & Materials (KIMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Jae-Hyun
JH
Kim
Department of Nano-Mechatronics, Korea University of Science & Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.|Center for Advanced Meta-Materials (CAMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Hak-Joo
HJ
Lee
Department of Nano-Mechatronics, Korea University of Science & Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.|Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery & Materials (KIMM) , 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
Kwang-Seop
http://orcid.org/0000-0003-4939-1973
KS
Kim
adhesion; confinement effect; rate-dependent adhesion; reversible transfer process; thin elastomeric film