Engineers invent a bubble-pen to write with nanoparticles

January 14, 2016
Engineers invent a bubble-pen to write with nanoparticles

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have solved a problem in micro- and nanofabrication—how to quickly, gently and precisely handle tiny particles—that will allow researchers to more easily build tiny machines, biomedical sensors, optical computers, solar panels and other devices.

They have developed a device and , called bubble-pen , that can efficiently handle nanoparticles—the tiny pieces of gold, silicon and other materials used in nanomanufacturing. The new method relies on microbubbles to inscribe, or write, nanoparticles onto a surface.

Researchers' interest in nanoparticles, which are between 1 and 100 nanometers in size, has grown rapidly because of their versatility and strength. Some nanoparticles have optical properties that are useful for electronics. Others have the ability to absorb solar energy. In biomedical applications, nanoparticles can serve as drug carriers or imaging agents.

But working with these particles while keeping their properties and functions intact can be difficult. And existing lithography methods, which are used to etch or pattern materials on a substrate, are not capable of fixing nanoparticles to a specific location with precise and arbitrary control.

A research team led by Texas Engineering assistant professor Yuebing Zheng has invented a way to handle these small particles and lock them into position without damaging them. Using microbubbles to gently transport the particles, the bubble-pen lithography technique can quickly arrange particles in various shapes, sizes, compositions and distances between nanostructures. This advanced control is key to harnessing their properties. The team, which includes Cockrell School associate professor Deji Akinwande and professor Andrew Dunn, describe their patented device and technique in a paper published in the Jan. 13 issue of Nano Letters.

The video will load shortly
Engineers at the Cockrell School of Engineering show bubble-pen lithography in action, including the generation of a microbubble and the depositing of nanoparticles in the shape of a UT Austin Longhorn. Credit: Cockrell School of Engineering

Using their bubble-pen device, the researchers focus a laser underneath a sheet of gold nanoislands (nanoscale islands) to generate a hotspot that creates a microbubble out of vaporized water. The bubble attracts and captures a nanoparticle through a combination of gas pressure, thermal and surface tension, surface adhesion and convection. The laser then steers the microbubble to move the nanoparticle on a site on the surface. When the laser is turned off, the microbubble disappears, leaving the particle on the surface. If necessary, the researchers can expand or reduce the size of the microbubble by increasing or decreasing the laser beam's power.

"The ability to control a single nanoparticle and fix it to a substrate without damaging it could open up great opportunities for the creation of new materials and devices," Zheng said. "The capability of arranging the particles will help to advance a class of new materials, known as metamaterials, with properties and functions that do not exist in current natural materials."

The technique could be especially helpful for science and medicine because researchers would be able to precisely control cells, biological material, bacteria or viruses for study and testing, Zheng added.

Moreover, bubble-pen lithography can leverage a design software program in the same way as a 3-D printer, so it can deposit in real time in a pre-programmed pattern or design. The researchers were able to write the UT Austin Longhorn symbol and create a dome shape out of nanoparticle beads.

In comparison to other existing lithography methods, bubble-pen lithography has several advantages, Zheng says. First, the technique can be used to test prototypes and ideas for devices and materials more quickly. Second, the technique has the potential for large-scale, low-cost manufacturing of nanomaterials and devices. Other lithography techniques require more resources and a clean room environment.

Zheng says he hopes to advance bubble-pen lithography by developing a multiple-beam processing technique for industrial-level production of nanomaterials and nanodevices. He is also planning to develop a portable version of the technique that works like a mobile phone for use in prototyping and disease diagnosis.

This research received funding from the Beckman Young Investigator Award.

Explore further: New nanomanufacturing technique advances imaging, biosensing technology

Related Stories

Scientists convert microbubbles to nanoparticles

March 30, 2015

Biomedical researchers led by Dr. Gang Zheng at Princess Margaret Cancer Centre have successfully converted microbubble technology already used in diagnostic imaging into nanoparticles that stay trapped in tumours to potentially ...

Exceptionally strong and lightweight new metal created

December 23, 2015

A team led by researchers from the UCLA Henry Samueli School of Engineering and Applied Science has created a super-strong yet light structural metal with extremely high specific strength and modulus, or stiffness-to-weight ...

Doping crystals of nanocrystals

September 24, 2015

Silicon semiconductors form the basis of all modern electronics and microprocessors. Crucial to these applications is the ability to 'dope' the semiconductor; which is to say, by controllably adding impurity atoms to a semiconductor, ...

Recommended for you

Nano-decoy lures human influenza A virus to its doom

October 25, 2016

To infect its victims, influenza A heads for the lungs, where it latches onto sialic acid on the surface of cells. So researchers created the perfect decoy: A carefully constructed spherical nanoparticle coated in sialic ...

New method increases energy density in lithium batteries

October 24, 2016

Yuan Yang, assistant professor of materials science and engineering at Columbia Engineering, has developed a new method to increase the energy density of lithium (Li-ion) batteries. He has built a trilayer structure that ...

Nanofiber coating prevents infections of prosthetic joints

October 24, 2016

In a proof-of-concept study with mice, scientists at The Johns Hopkins University show that a novel coating they made with antibiotic-releasing nanofibers has the potential to better prevent at least some serious bacterial ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.