We are investigating how patterned features crated via optical, physical, and chemical methods control the interface properties. Since the surface topographic properties can control the interface properties like adhesion and wettability properties, we exploited custom-designed surfaces for photonics and microfluidic applications. We created patterns onto a quartz coverslip using a femtosecond laser to have well-defined biological cell alignment [1]. By replicating the rose-petal inspired surfaces created on the polymer (PMMA) via femtosecond laser patterning onto a flexible soft elastomer (PDMS) using the soft lithographic technique, we demonstrated the surfaces that exhibit superhydrophobicity and underwater superaerophobicity for the first time [2-3]. Such superhydrophobic surfaces were further exploited for open microfluidic applications via grafting a stimuli-responsive polymer (PNIPAM) [4] and by incorporating plasmonic nanoparticles via in-situ reduction, we achieved superhydrophobic surface-enhanced Raman scattering substrates [5]. These photonic substrates provide the advantage of concentration enrichment while providing a large Raman scattering enhancement factor that allows detection of the femtomolar concentration of the analyte molecules. Further by chemically modifying the surface, the control of air bubble dynamics onto the surface was demonstrated [6]. The use of air-bubble mediated capillary forces to control the motion of floating objects at the air-water interface was also shown [7]. Recently, an omniphobic nanoporous alumina surface was created via evaporative deposition of poly(dimethylsiloxane) [8]. In pursuit to create a cost-effective plasmonic droplet analytic assay platform, we demonstrated by exploiting a water contact angle difference of 1800, it is possible to self-partition a sliding microliter droplet into picoliter droplets [9].This could find wide applications in chemical analysis and biological sciences.  In addition, the surface properties of polymeric nanoparticles has been demonstrated as more efficient anti-corrosive coating compared to its bulk counter part [10-11] Recently, we created oil grafted surfaces that facilitate efficient underwater bubble adhesion and transport. Much work on nature-inspired surface engineering in the field of biomedical devices, photonics, and sensors is in progress.

1) Applied Surface Science,305, 375-381 (2014)

2) Materials and Design, 100, 8-18 (2016)

3) Advanced Materials and Interfaces, 1601088 (2017)

4) ACS Applied Materials and Interfaces 9(33), 28046-28054 (2017)

5) Sensors and Actuators B: Chemical, 272, 485-493 (2018)

6) Applied Surface Science, 410, 117-125 (2017)

7) Advanced Materials and Interfaces, 1601088 (2017) (Wiley HOT article)

8) Bulletin of Materials Science, 43, 193 (2020)- (Invited Original Article)

9) Applied Surface Science, 571, 15188 (2022)

10) International Journal of Biological Macromolecules, 182, 2117-2129 (2021) 

11) Surfaces and Interfaces, 26, 10418 (2021)