Research Highlights

The field of liquid metals was highlighted by C&E News as one of the “top research” of the year in 2016.

Congratulations to Rashed and John.  This paper describes the use of electrochemical potential to remove the oxide skin from liquid metal locally, and thereby induce localized capillary withdrawal from a liquid metal film.  The work was highlighted by Wiley’s “Advanced Science News.”

Congratulations to Collin for this comprehensive review of methods to control interfacial tension of liquid metals using voltage.  The work is published in Applied Physics Reviews.

Our work on liquid metal was highlighted in C&E News.

Dickey provides a News and Views contribution describing the beautiful work of Prof. Jennifer Lewis (Harvard) on 4D Biomimetic Printing.

Congratulations to Yiliang and Collin, who led this work, along with Wang and Andre who played important roles.  This paper, published in Extreme Mechanics Letters, shows it is possible to form wires of liquid metal by simply stretching a droplet of the metal in a visco-elastic polymer matrix.

Congratulations to Dishit, Collin, and Laza for their paper being accepted in Lab on a Chip.  The paper describes the ability to 3D printing microfluidic channels in 3D space using liquid metals as sacrificial ink.  After printing the metal and embedding it in polymer, the metal can be removed from the structure to leave behind hollow microchannels.

This February issue of MRS Bulletin covers unconventional lithographic techniques.

Funsize physics is a site to promote interesting science topics to the general public and children.  Here is a link to our article.

Congratulations to Dishit for all his hard work toward this book chapter.  The book chapter describes incorporating electronics into 3D printed objects with a focus on “multi-functional” printing.

Congratulations to our collaborators, Yue and Prof. Gu who led this work.  The work shows that liquid metal nanoparticles are effective at delivering cancer drugs.  Perhaps equally importantly, the work shows that EGaIn (eutectic gallium indium) has low toxicity in mouse studies.

Congrats to Shiyang, Ishan, and Yiliang for their paper published in Advanced Materials.  The paper describes the formation of liquid metal droplets using microfluidic flow focusing (pumping liquid metal and another immiscible fluid through a small orifice).  The unique aspect of this work is the ability to control the diameter of the droplets by applying a voltage that changes the surface tension in real time.

Congratulations to Yiliang and Chris on their paper published in Small. This work shows it is possible to “draw on demand” conductive circuit boards and antennas by embedding a film of liquid metal droplets between two sheets of elastomer.  Pressing on these particles causes them to merge to form conductive traces for soft circuit boards.

Our collaboration with Prof. Adams group (published in J. of Applied Physics) was highlighted in IEEE Spectrum.  The work shows it is possible to use voltage to tune the length of antennas composed of liquid metal.

Congratulations to Shiyang, Ishan, and Yiliang for their paper published in Lab on a Chip.  The work shows it is possible to use voltage to steer the direction that liquid metal flows as it is pumped through microchannels.

Congrats to Ishan and Hudson for this nice mini-review published in Journal of Materials Chemistry C.  It was a pleasure working with our friend, Carmel Majidi. The paper was selected as a “Hot Paper of 2015” by Royal Society of Chemistry.  The paper can be found here. 

Congratulations to Rashed and Chris for having their work highlighted in Advanced Functional Materials.  Recapillarity utilizes reductive reactions to remove the oxide layer from liquid metal and thereby induce capillary behavior.

Michael Dickey gave a talk on liquid metal for the TEDx session on the theme “flow”, recorded at NCSSM.  The title of the talk was “Liquid Metal: The Prophecy of the Terminator”.

Our groups reearch was featured on the show El Hormiguero.  It is a spanish show broadcast all over South American and in some of Asia.  They invited us to demonstrate our research on liquid metal.  Nicole Kidman was the other guest on the show.  The show was recorded in London and airs January 2015.

This review article is a spotlight on applications of liquid metals based on gallium.

Our work on shape reconfigurable liquid metal was featured on the late night comedy show, Seth Meyers.

Congratulations to Rashed and Collin.

This work describes the use of low voltages (~1 V) to deposit and remove surface oxides from gallium based liquid alloys.  The deposition of the oxide lowers the surface tension and the removal increases the surface tension.  Combined, these two techniques provide unprecedented control over the shape of liquid metals with low toxicity.  It also represents a facile way to tune the interfacial tension of metals from nearly 500 mN/m to nearly zero in a reversible manner using ~1 V.  This change in tension is the largest ever reported for fluids at room temperature (to the best of our knowledge).  The paper can be found here.

Congratulations to Ying, Hayley, and James.  Link to paper.

Congratulations to Ying.

Congratulations to Ying!  This collaborative work with Jan Genzer and Yong Zhu describes a simple way to correlate surface temperature to folding angle for our self-folding process.  The paper can be found here.

Congratulations to Daniel Morales for this feature of his work, done in collaboration with Orlin Velev.

This paper was most downloaded paper in the journal for the month it went online (summer 2013)

Congratulations to Etienne and Daniel for this collaborative work with Orlin Velev’s group. The work is published in Nature Communications.  The term “ionoprinting” refers to the injection of copper ions (Cu2+) from a copper electrode into a hydrogel. The ions bind to the gel to create lateral and topographical patterns of ions. The binding of the ions changes the local modulus and also induces stress that can be sufficient to cause rapid motion. This motion may be useful for soft robotics and biomimetic actuators. The work was supported by the NSF MRSEC. The work will be highlighted in Scientific American

Congrats to Collin for having his first paper published!  This paper, which appears in Advanced Materials, describes methods for patterning liquid metals at room temperature in 3D space. The work has been highlighted by Nature, NBC, NY Times, BBC, and many other places

Congrats to Lin and Kenny for having this paper published in Soft Matter  The work was collaborative with Prof. Spontak at NC State. The work describes ways to make ultra-stretchable microfluidic channels, which are useful for forming stretchable conductors. The work was highlighted on the RSC blog as one of three ‘hot’ papers for the month of July.

Work done in collaboration with Jan Genzer and featuring our students, Ying Liu and Brandi Shaw.

Congrats to Mohammed for having his first paper published!  This paper describes the fabrication of soft diffraction gratings by forming buckles on the walls of microfluidic channels filled with gallium liquid metal alloys.

This article, which will be featured in Advanced Materials, describes the fabrication of self-healing stretchable wires formed by embedding liquid metal wires in microchannels composed of self-healing polymer. These stretchable wires can be completely severed with scissors and rapidly self-heal both mechanically and electrically at ambient conditions.  By cutting the channels strategically, the pieces can be re-assembled in a different order to form complex microfluidic networks in 2D or 3D space.

Link to paper

Our paper on stretchable wires appears in the weekend edition of the Wall Street Journal.

Congratulations to Shu, Ju-Hee, Sharvil, and Robin.

Link to paper

NBC highlights research

Congrats to Robin and Dhana!  This paper describes thiol-ene materials as new emedding materials for nanoskiving.  These materials provide better adhesion to gold and have ideal mechanical properties for microtome sectioning.

Reuters visited our lab and put together a feature piece on the self-folding work being done with Prof. Genzer and Ying Liu.  Enjoy!

Congratulations to Rashed and Gerry.  This work describes shape reconfigurable microstrip filters.

This award recognizes research excellence over the past three years in the College of Engineering at NC State.  This award is a tribute to the hard work of the students in the group.

Ying’s research on self-folding polymer sheets was featured on the cover of Soft Matter.  The paper was one of the top 10 most downloaded articles from the journal for several months.  The video on youtube received ~200k hits.

The Schoenborn symposium is a departmental research symposium that includes a poster competition chosen by graduate students.  Congratulations to Rashed for being recognized with the best poster.

Dickey receives young investigator award for research excellence.

Our work on stretchable antennas is highlighted in The Economist, MSNBC, Forbes, Wired, MIT Technology Review, etc.  Congratulations to Ju-Hee, Gerry, Amit, and Jacob!