University of Illinois at Urbana-Champaign

Energy Transport Research Lab


  • Scalable copper oxide (CuO) nanostructure

  • The modes of water vapor condensation

  • Charged jumping droplets from a cooled tube

  • Condensation on superhydrophobic CNTs

  • Heart shaped CuO nanostructure

  • Condensation on silicon nanopillars

  • Long exposure-time images of jumping-droplets

  • Frozen droplet on a nanostructured surface

  • Jumping-droplet electrostatic generator device

  • Kissing silicon nanopillars

  • Metal oxide nanoflower "garden"

  • Water droplet "pearl" on CNT nanograss

  • Water evaporation on Si nanopillars

  • Droplet pinning Si nanopillars

  • Water evaporation on Si nanopillars

  • Zinc oxide nanowires

  • Water droplet placed on a clean CuO surface

  • Water droplet placed on a coated CuO surface

  • ETRL Fall 2014

  • Group Outing at Golden Harbor Restaurant Fall 2014

  • Group Outing at B Won Restaurant Spring 2015

  • 9th Boiling and Condensation Conference - Boulder, Colorado, 2015

  • InterPACK - San Francisco, California, Summer 2015

  • Group BBQ at the Miljkovic residence, Summer 2015

  • BP Invited Talk - London, UK, Fall 2015 - Meeting with John Rose and his wife

  • Kyushu University - Japan, Winter 2016 - Photo with Takata Sensei

  • Kyushu University - Japan, Winter 2016 - Photo with Professor Xing Zhang of Tsinghua University

  • Kyushu University - Japan - Winter 2016 - Photo with student doing ESEM

  • Kyushu University - Japan - Winter 2016 - Photo with Dr. Dani Orejon

  • Group Outing at Sitara Restaurant, Winter 2016

  • Group BBQ at the Miljkovic residence, Spring 2016

  • Nano/Microscale Phase Change Workshop in Trondheim, Norway - Summer 2016

  • Nano/Microscale Phase Change Workshop in Trondheim, Norway - Summer 2016

  • View of Trondheim, Norway - Summer 2016

  • Group photo at ISFV2016 in Tennessee - Summer 2016

  • Hiro receiving a plaque from his colleagues

  • Group outing at Black Dog BBQ - Summer 2016

  • Group outing at Black Dog BBQ - Summer 2016

  • ASME Summer Heat Transfer Conference - Washington DC, Summer 2016

  • ETRL Group Photo - Inside - September 2, 2016

  • ETRL Group Photo - Outside - September 2, 2016

  • Group Outing at Sun Singer - October 22, 2016

  • Shreyas Chavan and James Carpenter testing superhydrophobicity

  • Patrick Birbarah and Junho Oh testing jumping droplet cooling of GaN semiconductor

  • Patty Weisensee and Tuanyu Yang measuring droplet distributions during condensation on SLIPS

  • Jesus Sotelo and Kalyan Boyina installing a superhydrophobic evaporator coil inside the vacuum chamber

  • Junho Oh and Alp Gunay measuring the advancing contact angle on a superhydrophobic sample

  • Hyeongyun Cha and Nenad Miljkovic observing water droplet condensation on the optical mocroscope

  • Group Outing at Silver Creek - November 2, 2016

  • Patty Weisensee defends her PhD thesis - November 7, 2016

  • Patty Weisensee defends her PhD thesis - November 7, 2016

  • Gordon Research Conference - January 11, 2017

  • Group Outing at Silver Creek - April 9, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • Group BBQ at Nenad's home in Urbana - May 19, 2017

  • ASME Summer Heat Transfer Conference - Bellevue, Washington State, Summer 2017

  • Kyushu University in Japan Visit - Dani Orejon and XPS

  • Dinner at fish restaurant courtosey of Takata-sensei's group

  • Visit to Daikin in Osaka, Japan

  • Uni High School 2015

  • Uni High School 2015

  • Uni High School 2015

  • Uni High School 2015

  • Uni High School 2015

  • Uni High School 2015

  • GAMES Camp 2015

  • GAMES Camp 2015

  • GAMES Camp 2015

  • GAMES Camp 2015

  • GAMES Camp 2015

  • GAMES Camp 2015

  • Elementary School Demonstrations 2016

  • Elementary School Demonstrations 2016

  • Elementary School Demonstrations 2016

  • Elementary School Demonstrations 2016

  • Elementary School Demonstrations 2016

  • Elementary School Demonstrations 2016

Droplet Impact on Elastic Superhydrophobic Surfaces


High speed videos of droplet impact on elastic or flexible superhydrophobic surfaces. The surface elasticity causes droplet 'springboarding' and lower droplet contact times.

Charged Droplets


Nenad discusses his previous work on condensation, nanodroplet formation, and new nanopatterned surfaces that could boost the efficiency of power plants and desalination systems.

Charged Droplets


Droplets falling from a superhydrophobic surface are drawn toward an electrically charged wire, bottom center, demonstrating that they carry an electric charge.

Dynamics of Coalescence-Induced Jumping Water Droplets


This fluid dynamics video shows the different interaction mechanisms of coalescence-induced droplet jumping during condensation on a nanostructured superhydrophobic surface. High speed imaging was used to show jumping behavior on superhydrophobic copper oxide and carbon nanotube surfaces. Videos demonstrating multi-jumping droplets, jumping droplet return to the surface, and droplet-droplet electrostatic repulsions were analyzed. Experiments using external electric fields in conjunction with high speed imaging in a custom built experimental chamber were used to show that all coalescence-induced jumping droplets on superhydrophobic surfaces become positively charged upon leaving the surface, which is detailed in the video.

Jumping water droplets improve power-plant efficiency


The efficiency of most industrial plants depends crucially on water vapor condensing on metal plates or condensers, and how easily the condensed water can fall away allowing for more droplets to form. On a typical, flat-plate condenser, water vapor condenses to form a liquid film on the surface, drastically reducing the condenser's ability to collect more water, and ultimately acting as a barrier to heat transfer.

By creating hydrophobic surfaces, either through chemical treatment or through surface patterning, researchers have been able to prevent this problem by encouraging water droplets to form and fall away. Now, we have taken this process a step further by making surfaces that are patterned at multiple scales.

The energy, released as tiny droplets of water that merge to form larger ones, is enough to propel the droplets upward from the surface. The removal of droplets doesn't depend solely on gravity — droplets don't just fall from the surface — they actually JUMP away from it.