Stephen A. Morin's research while affiliated with University of Nebraska at Lincoln and other places

... Their anisotropic nature has permitted diverse applications ranging from stimuli-responsive drug delivery carriers [3,4] to active swimmers with controlled movement [5,6]. Among the various types of Janus particles [7,8], zwitterionic particles with oppositely charged surface regions, also termed inverse patchy colloids, represent an important class [4,[9][10][11][12][13][14][15][16][17]. For example, by coating the hemispheres with weak polymeric acid and base groups, pH-driven aggregation and disaggregation can be efficiently achieved [11,12]. ...

... where θ is the measured WCA for PDMS nanocomposites; r is the surface roughness of PDMS nanocomposites; θ e is the equilibrium WCA on the smooth PDMS surface; and f s is the solid fraction of the solid-air compound surface [18]. Due to the inherent hydrophobicity of PDMS, superhydrophobicity can be achieved simply by roughening the surface of pure PDMS or its nanocomposites to increase the r value and/or decrease the f s value, using various techniques: spin coating [108], electrospinning [109], dropcasting or spray-coating [110][111][112][113], replication [17,[114][115][116][117][118][119], laser engraving [120][121][122][123][124][125], introducing a sacrificial template [126], wrinkling [127], 3D printing [20,128], and other methods [129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144][145][146][147]. Although the exact method or resultant morphology may differ, they have the same goal of introducing micro-and nanoscale or hierarchical roughness (higher r and/or lower f s values) into the hydrophobic PDMS-based material to achieve superhydrophobicity. ...

... By introducing chemical/structure wetting gradients, the lateral adhesion force along the droplet contact line can be modulated, and its effect is switched from resisting to driving. [19][20][21] Thus, droplets can be spontaneously steered without external energy consumption. ...

... Soft actuators represent an exciting new technology with the capacity to transform multiple industries, ranging from healthcare to robotics. One of the most notable breakthroughs in the field of SSAs is the creation of multiresponsive versions, which present numerous benefits compared to mono-responsive types [176][177][178]. The improved functionality of multi-responsive soft actuators is a crucial advantage. ...

... Many researchers are trying to elucidate the mechanistic pathway underlying the synthesis of these tiny magnetic structures as they can be exploited for biotechnology and nanotechnology purposes. However, they are limited owing to the fact that these bacteria are difficult to isolate from the deep ocean samples and also difficult to handle under laboratory conditions due to their fastidious nature (Stoller et al., 2020). Furthermore, the synthesis of magnetosomes is a very tidy process controlled by a complex set of genetic components (Jogler and Schuler, 2009). ...

... Enormous efforts have been spent on inhibiting dewetting during film processing. For example, attempts have been made in hydrophilizing the PDMS surface through surface grafting, 15,16 O 2 plasma 17,18 and UV/ozone 19,20 treatment, and addition of small amounts of nanoparticles. 21,22 Meanwhile, progressive understandings on the nonequilibrium behavior of pre-prepared thin films 23−25 promote greatly in achieving more stable films without dewetting after processing. ...

... Before controlling the robot ' s action, the first key problem to be solved is to obtain accurate and reliable information. Sensing can greatly reduce the risk of damage to external objects through better displacement accuracy, pressure accuracy and temperature accuracy [88][89][90][91][92]. Soft robots often require connections with rigid machine sensing, control systems and energy sources. ...

... However, standard photolithography creates patterns that have fixed height in Z-direction, where the height of the micromold (and thus the resulting microfluidic structure depth) is determined by the thickness of the spincoated photoresist. This is why standard photolithography is being referred to as a 2.5-dimensional microfabrication technique, as it lacks the spatial Z-direction patterning capability that true 3-dimenstional fabrication methods such as 3D printing are capable of producing (Rose et al. 2019;Derkus 2016). Thus, for example in the microfluidic applications mentioned above, where two or more different heights are desired within the same microfluidic device, a two-step photolithography has to be employed by patterning the first layer, followed by spincoating the next photoresist layer on top of the first patterned layer, and then creating the second pattern on this second photoresist layer. ...

... The original technique was "borrowed" from the MEMS community. The earliest work of microfluidic performed using soft lithography [171,172] can be traced back to the Whiteside group [173,174]. The term "soft lithography" was first introduced back then, referring to a technique based on printing and replica molding using elastomeric soft materials and photomasks with the patterns of interest. ...

... 26 Finally, in some cases, the substrate may also contain surface heterogeneities, such as metal traces on flex circuits. 63 Having established the necessary parameters to bond PDMS, we next sought to demonstrate two approaches to use the properties of the liquid metal to make electrical connections. We demonstrate two strategies, although there are likely many ways to integrate stretchable conductors into PDMS. ...