1 Supplementary Information for 2

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4 Optoelectrofluidic behavior of metal–polymer hybrid

5 colloidal particles

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7 Dongsik Han, Hyundoo Hwang, and Je-Kyun Parka)

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9 Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology

10 (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea

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14 a) Electronic mail: [email protected] (J.-K. Park); Tel: +82-42-350-4315; Fax: +82-42-350- 15 4310. 16

1 1 2 1 Optically-induced AC electroosmosis (ACEO) flow in the optoelectrofluidic device 2

3 The ACEO flow could be observed with relatively small microbeads at the top and the

4 bottom surfaces as shown in Fig. S1. The particles came toward the light pattern near the bottom

5 surface. Then they showed vertical movement to the top electrode and moved away from the light

6 pattern along the top surface. These whole movements were in full accord with the distinguishing

7 feature of the ACEO flow in the optoelectrofluidic system.

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10 FIG. S1. Microscopic images showing the motion of 3 μm polystyrene particles at the top and

11 the bottom surfaces of the liquid chamber in this optoelectrofluidic device in the application of an

12 ac voltage of 20 Vpeak-peak with 100 kHz (scale bar: 5 μm). Left portions in each image are

13 optically-generated virtual electrodes.

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