In collaboration with the labs of Jerry Shan, Jeffrey Zahn, Hao Lin, and David Shreiber, along with Joel Maslow of our sponsor, GeneOne Life Science, Inc., and Rob Zipkin of Medchem 101, HMNL graduate student Sarah Park studied different strategies to manipulate the "charge landscape" in electrospray deposition to increase spray efficiency. In this way, we were able to achieve coatings that contained approximately 100% of the sprayed material on down to ~3 square mm of microneedle array from a spray needle located 4 cm away.
HMNL postdoc and former graduate student Michael Grzenda, in collaboration with the labs of Jeffrey Zahn in Biomedical Engineering and Andrei Jitianu from CUNY-Lehman, published an invited article in Coatings discussing the relative merits of different electrospray deposition modes of polymer coatings when targeting small templates. Unsurprisingly (at least to us), the self-limiting electrospray regime provides the most uniform coatings that extend beyond the edges of the template to the smallest extent.
In a joint effort with Prof. Marissa Tousley of Rose Hulman Institute of Technology, the HMNL reported results of the past several years of Virtual Research Group (VRG) pilots conducted at Rose Hulman and the New Jersey Governor's School for Engineering and Technology. These modules use a mix of real data from literature and simulated data to create a simulated experience of being in a research group that requires only minimal educational resources. The results showed that, among other findings, students found the VRG to be as enjoyable as conventional in-lab research experiences.
Professor Singer was recognized as an Early Career Materials Researcher by MRS Communications. The so-recognized letter discusses application of focused laser spike (FLaSk) thermocapillary dewetting as a tool for measuring the properties of thin films. This research, led by former lab member Tianxing "Tim" Ma and conducted in collaboration with the lab of Zahra Fakhraai of UPenn Chemistry, demonstrated that FLaSk can uncover properties related to molecular weight and shear-induced ordering in nanoscale soft matter films.
In a joint effort with former HMNL Postdoc Prof. Molla Hasan (at UT-Permian Basin), HMNL PhD candidate Yogin Patel has published research on the porous materials formulation as the inside back cover of the latest issue of Advanced Materials Interfaces. High shear mixing of immiscible liquids, surfactant, and nanoparticles create a macropore-infused nanocomposite emulsion thermosets (MINET) with tunable surface behavior and pore size.
In a joint effort with Prof. Assimina Pelegri here at Rutgers and Prof. Lin Lei at Chongqing Jiaotong University, HMNL PhD candidate Robert Green-Warren and former MS student, Luc Bontoux, led the investigation of the mechanical properties of thin films produced via self-limiting electrospray deposition (SLED). In this work, various polymers were composited, sprayed, and mechanically evaluated by nanoindentation.
In collaboration with Professor Mark Losego’s lab at Georgia Tech and former HMNL member Lin Lei at Chongqing Jiaotong University, HMNL member Catherine Nachtigal studied the application of atomic layer deposition (ALD) to methylcellulose nanowire forests deposited by self-limiting electrospray deposition (SLED). Applying a thin layer of ALD alumina made the nanowire forests superhydrophobic, while maintaining the conformal nature of both ALD and SLED.
The 2018-2019 HMNL Senior Design Team published their work on creating a thermocapillary dynamic spatial light modulator in Optics Letters. Here they showed for the first time that the thermocapillary dewetting could be used to make a dynamic optic. This method has the advantage of being able to operate with only a thin liquid layer over a high-quality reflective surface, meaning it could be applied to high power lasers. You can read the article here.
The HMNL and the Zahn and Zou Lab's recent work on self-limiting electrospray on thin film and dewetted templates has been published in Scientific Reports. The combination of laser dewetting and electrospray both brings together two of our lab's research thrusts and also is the first step to realizing the potential of developer-free lift-off. This work was funded by NSF award 1911518. You can read the article here.