Researchers from the School of Mechanical Engineering at Purdue University have developed an innovative new patterning approach for applications like drug delivery in biomedical applications. Detailing their research in the recently published ‘3D-Printed Microrobots with Integrated Structural Color for Identification and Tracking,’ the authors give us insight into new patterns on the micro- and nanoscale using two-photon polymerization (TPP), a technique that offers submicron resolution.
While microrobots (divided into biological, hybrid, and synthetic groups) are helpful in applications like micromanipulation and advanced sensing, there are still obstacles in development of miniature structures because of the need to combine actuation and wireless control within one device. Size is the issue in many cases, although actuation is often provided externally. There are also extensive challenges for in vitro and in vivo processes with the use of microrobotic systems, visuals, and tracking.
“For 3D printed microrobots with smaller dimensions, alternative fabrication approaches are needed to integrate distinctive tracking features, including marking the microrobot surfaces with fluorescent materials such as quantum dots or using fluorophores selectively attached to specific functional groups,” stated the researchers. “Despite their success in tracking, these materials lose their fluorescence over time, limiting their duration of usefulness.”
In this study, color plays a large role, with patterns comprised of prism arrays pointing upward—permitting the team to integrate them onto different areas of the microrobot. Patterns were developed as follows:
- Red pattern – blocks with a 160 nm x 170 nm footprint
- Green pattern – blocks with a footprint of 120 nm x 90 nm
- Arrays on both of the helix and platform microrobots consist of all red (R), all green (G), or alternating red and green (RG) blocks
“The RG pattern was shown to express a wider spectrum of colors in comparison to just R and the G patterns alone,” stated the researchers. “The R and G patterns expressed bright colors of blue and red only, whereas RG additionally expressed bright green.
“Fine tuning of color expression depending on the applied angle can potentially provide real-time information of a microrobot’s position in both x–y and z directions by identifying the change in color while it is moving in the 3D workspace.”
Helical microswimmers relied on rotating magnetic fields for actuators, while the control platform microrobots used gradient fields relying on the MagnebotiX coil system. The researchers noted that as the control platforms rotated, color was visible, as well as on the helical robots using low frequencies. The researchers did note though that color differed depending on orientation and light source.
“The variation of structural color block dimensions was used to explore the ability to manipulate color expression. In this study, the alternating block geometries provided a wider range of colors than arrays with a single type of block geometry,” concluded the researchers. “With increasing accuracy of micro-3D-printing technologies and by exploring complex patterns, noniridescent colors can be obtained.
“This has been recently demonstrated for 3D printed lamellar-like structures similar to the ones of the Morpho butterfly, though this type of pattern only expressed an artificial blue color and was not applied to structures while moving. By exploring new computationally designed structures and integrating them into 3D microrobotic systems, structural color can become a common element not only for tracking and identification but also for creating tunable surface properties.”
Microrobotics and drug delivery systems continue to be impacted by 3D printing in research projects involving innovative microstructures, spermbots, and a variety of different techniques. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: ‘3D-Printed Microrobots with Integrated Structural Color for Identification and Tracking’]
Subscribe to Our Email Newsletter
Stay up-to-date on all the latest news from the 3D printing industry and receive information and offers from third party vendors.
You May Also Like
A First-Timer’s “Definitive” Guide to Surviving Formnext
Believe it or not, this year was my very first time attending the additive manufacturing (AM) industry powerhouse event known as formnext, which has been held in Germany for eight...
3D Printing Webinar and Event Roundup: November 27, 2022
Coming off of Thanksgiving in the U.S., we’re still at low mass when it comes to 3D printing webinars and events, but there are still a few offerings this week,...
3D Printing News Briefs, November 23, 2022: ESD-Safe Resin, Edible QR Codes, & More
In today’s 3D Printing News Briefs, AM Solutions has joined the ColdMetalFusion Alliance, AMFG is partnering with French 3D printing service bureau Erpro Group, and AddUp and the WBA are...
3D Printing Financials: voxeljet Q3 Earnings Results Miss on Revenue, Net Loss Widens
Pioneering 3D printer manufacturer voxeljet (NASDAQ: VJET) reported its latest round of earnings last week, missing on revenue and earning expectations. The German company’s revenue was €5.7 million for the...