1 Supporting Information for Hydrophilic/Hydrophobic Interphase-Mediated Bubble-Like Stretchable Janus Ultrathin Films Towards Self-Adaptive and Pneumatic Multifunctional Electronics Peng Xiao,, Yun Liang,, Jiang He,, Lei Zhang, * Shuai Wang,, Jincui Gu, Jiawei Zhang,, Youju Huang,, Shiao-Wei Kuo and Tao Chen, * Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Zhongguan West Road 1219, 315201, Ningbo, China. University of Chinese Academy of Science, Beijing 100049, China. Department of Material and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, 804, Kaohsiung, Taiwan.
2 Figure S1 The Janus films fabricated at air/water interface were further transferred onto targeted substrates from the air side of the films, resulting in the direct contact with the substrate surfaces. Figure S2 Photos of lifting ultrathin film lifted up from the water surface.
3 Figure S3 Photos of transferring CNTs/PDMS film onto the edge of the beaker to form a selfsupported one. Figure S4 a) Schematic illustration of pneumatic tests with pure PDMS with the thickness of about 50 μm by conventional method and ultrathin film with the thickness of about 15 μm using our method. b) The curvature induced by the actuated inflation versus applied pressure curves of pure PDMS and our ultrathin film.
4 Figure S5 The Janus CNTs/PDMS film with the thickness of about 15 μm was seamlessly attached onto the edge of the chamber to explore the maximum tolerable pressure with good self-sealing property. Figure S6 SEM images of the cross-sectional film.
5 Figure S7 The stress versus strain curves of the pure PDMS and CNTs/PDMS films. Figure S8 The schematic fabrication of CNTs film at air/water interface.
Figure S9 AFM and SEM characterization of the CNTs film compression process. a) Schematic of capillary force driving compression of the CNTs network. b) AFM images and c) SEM images of the CNTs network during the compression process. 6
7 Figure S10 Raman spectrum of CNTs with COOH groups. Figure S11 The PDMS layer of the Janus film was directly attched onto the surface of the hand skin for up to 12 h with the temperature of about 18ºC and relative humidity of about 49%. The invited volunteer demonstrated no apparent discomfort, red and swollen phenomenon, etc.
8 Figure S12 Photos of attaching ultrathin film (the thickness is about 2.3 μm) to hand surface. a) The dried film on skin surface. b) Film bending behavior without any breakage. c) A lot of film fragments left on the skin after peeling off the film. Figure S13 Photographs of CNTs films with different concentration before and after PDMS asymmetric modification.
9 Figure S14 Resistance versus cycles curve, demonstrating a good stability after 1000 bendingreleasing cycles. Figure S15 Current versus temperature spectrum of the Janus hybrid film.
10 Figure S16 Current versus time spectra with/without inflation behaviors at fixed temperature and humidity. Figure S17 Schematic of the self-adaptive process and response behavior of the film.
11 Figure S18 Pictures of the film behavior before and after the lid onto the flask. Figure S19 Real-time monitoring motion behavior of self-supported film on the flask at different temperature.
12 Figure S20 Photographs of sunlight irradiation can heat the air inside the bottle, which can indirectly induce the film buldge (the temperature is 19 C and the sunlight intensity is 650 W/m 2 ). Figure S21 Film adhered onto the flask driven by the human hand and the corresponding current change during the heating process.
13 Figure S22 a) The sketch of a proof model of visual alarm to detect the high temperature. b) Photos of the model driven by the temperature. Figure S23 A home-made actuator that can actuate the mung to move to the desired bottle, which is driven by the light induced air expansion inside the flask.
14 Figure S24 Current change vs. time curve, detecting a typical movement (a pill-bug that was about 20 mg weight, was put on the film surface, rolled and left). Figure S25 Current-time curves, showing the relative current change for different single word phonations.
15 Figure S26 Current-time curve with a sentence. a) 1, 2, 3, 4, 1234 and b) One World One Dream. Figure S27 The amplified electrical waveform with the musical signal in Figure 6g.
16 Figure S28 Actuating force versus time curves and actuating force versus applied air pressure curve. Figure S29 The maximum actuated frequency the film could be endured.
Figure S30 a) Schematic illustration of the integrated actuator with controlled moving behaviors in water. b) Photos of the controlled actuation driven by the pressure. 17