Magnetic liquid marbles, their manipulation and application in optical probing

Abstract

Magnetic liquid marbles, an encapsulation of liquid droplet with hydrophobic magnetic particles, show remarkable responsiveness to external magnetic force and great potential to be used as a discrete droplet microfluidic system. In this study, we presented the manipulation of a magnetic liquid marble under an external magnetic field and calculated the maximum frictional force, the magnetic force required for actuating the liquid marbles and the effective surface tension of the magnetic liquid marble, as well as the threshold volume for the transition from quasispherical to puddle-like shape. By taking advantage of the unique feature of being opened and closed reversibly, we have proven the encapsulated droplets can be detected optically with a reflection-mode probe. Combining the open-close and optical detection also enables to probe chemical reactions taking place within liquid marbles. These remarkable features offer a simple yet powerful alternative to conventional discrete microfluidic systems and may have wide applications in biomedical and drug discovery.

Glycerol as high‐permittivity liquid filler in dielectric silicone elastomers

“…The idea of using high-permittivity polar liquids as fillers in dielectric elastomers was also supported in a concept of generating water marbles that are responsive to high electric and magnetic fields. [24][25][26][27] Liquid marbles are often described as non-stick droplets coated with micrometer-sized hydrophobic particles. [28] The liquid marbles were proven to actuate upon exposure to sufficiently high electric fields.…”

Interpretation of elasticity of liquid marbles

“…A variety of media, including organic and ionic liquids and liquid metals, could be converted into liquid marbles [16][17][18]. Liquid marbles were successfully exploited for microfluidics [1,4,[18][19][20][21], water pollution detection [22], gas sensing [23], blood typing [24] and optical probing [25]. Respirable liquid marbles for the cultivation of microorganisms and Daniel cells based on liquid marbles were reported recently by Shen et al [26][27].…”

Liquid marbles containing petroleum and their properties

“…Liquid marbles were successfully exploited for microfluidics (Venkateswara Rao et al 2005;Xue et al 2010;Bormashenko et al 2008Bormashenko et al , 2011Bormashenko et al , 2012, water pollution detection (Bormashenko and Musin 2009), gas sensing (Tian et al 2010), electrowetting (Newton et al 2007), blood typing (Arbatan et al 2012), and optical probing (Zhao et al 2012). Respirable liquid marbles for the cultivation of microorganisms and Daniel cells based on liquid marbles were reported recently by the group led by Shen Li et al 2013).…”