Reconfigurable Magnetic Liquid Metal Robot for High-Performance Droplet Manipulation.

Droplet manipulation is crucial for diverse applications ranging from bioassay to medical diagnosis. Current magnetic-field-driven manipulation strategies are mainly based on fixed or partially tunable structures, which limits their flexibility and versatility. Here, a reconfigurable magnetic liquid metal robot (MLMR) is proposed to address these challenges. Diverse droplet manipulation behaviors including steady transport, oscillatory transport, and release can be achieved by the MLMR, and their underlying physical mechanisms are revealed. Moreover, benefiting from the magnetic-field-induced active deformability and temperature-induced phase transition characteristics, its droplet-loading capacity and shape-locking/unlocking switching can be flexibly adjusted. Because of the fluidity-based adaptive deformability, MLMR can manipulate droplets in challenging confined environments. Significantly, MLMR can accomplish cooperative manipulation of multiple droplets efficiently through on-demand self-splitting and merging. The high-performance droplet manipulation using the reconfigurable and multifunctional MLMR unfolds new potential in microfluidics, biochemistry, and other interdisciplinary fields.

Directional sweat transport of monolayered cotton-fabrics fabricated through femtosecond-laser induced hydrophilization for personal moisture and thermal management.

Personal moisture and thermal management fabrics that can facilitate sweat removal and regulating skin temperature are highly desired for improving human comfort and performance. Here, we demonstrate a hydrophobic/superhydrophilic Janus cotton-fabric through femtosecond-laser-induced hydrophilization. The engineering Janus cotton-fabric can unidirectionally transport human sweat spontaneously. More importantly, the Janus fabrics can maintain human body temperature 2-3 °C lower than the conventional cotton fabrics, implying the cooling effect in thermal environment. In addition, the Janus fabric has lower wet skin adhesion in comparison with a conventional hydrophilic cotton fabric. The water vapor transmission rate (WVTR) of a Janus fabric is comparable to the traditional hydrophilic cotton fabrics. Overall, the successful creation of the Janus fabrics provides new insights for the development of moisture-wicking/thermal-management fabrics for satisfying the growing demand of personal comfort.

High-performance blood plasma separation based on a Janus membrane technique and RBC agglutination reaction.

Separation of plasma which is full of various biomarkers is critical for clinical diagnosis. However, the point-of-care plasma separation often relies on microfluidic filtration membranes which are usually limited in purity, yield, hemolysis, extraction speed, hematocrit level, and protein recovery. Here, we have developed a high-performance plasma membrane separation technique based on a Janus membrane and red blood cell (RBC) agglutination reaction. The RBC agglutination reaction can form larger RBC aggregates to separate plasma from blood cells. Then, the Janus membrane, serving as a multipore microfilter to block large RBC aggregates, allows the plasma to flow from the hydrophobic side to its hydrophilic side spontaneously. As a result, the separation technique can extract highly-purified plasma (99.99%) from whole blood with an ultra-high plasma yield (∼80%) in ∼80 s. Additionally, the separation technique is independent of the hematocrit level and can avoid hemolysis.

3D microfluidic cloth-based analytical devices on a single piece of cloth by one-step laser hydrophilicity modification.

In this work, we report for the first time a simple and robust method for constructing a 3D microfluidic analytical device on a single piece of hydrophobic cotton cloth. Specifically, laser scanning technology was applied to process hydrophilic regions at the top and bottom of a single piece of hydrophobic cloth. Symmetrical hydrophilic regions at the bottom and top constituted vertical microfluidic channels, and asymmetrical hydrophilic regions constituted transverse flow channels. Liquid flow velocity in 3D cloth-based microchannels can be adjusted flexibly by modifying laser parameters, and programmable laser scanning can be utilized to process 3D microfluidic devices with various patterns. Single-piece 3D cloth-based microfluidic devices formed via this method can be used in many fields such as information encryption and anti-counterfeiting, multi-liquid printing and liquid mixing dilution. Compared to traditional processing methods of 3D cloth-based microfluidic devices, the laser scanning method eliminates multiple complex and repetitive assembly processes, which is a significant advance in this research area. This processing method provides a new option for fast and large-scale manufacturing of 3D cloth-based microfluidic analysis devices for point-of-care testing application in undeveloped regions/countries.

[Monthly changes in caloric values of five shrubby Palmae species leaves].

Studies on the monthly changes in the ash contents and caloric values of 5 shrubby Palmae species (Chamaerops humilis, Rhapis gracilis, Sabal minor, Chamaedorea cataractarum, Chamaedorea brachypoda) leaves showed that annual average ash content of the five shrubby species was 4.87% +/- 1.37% for Chamaerops humilis, 8.33% +/- 0.89% for Rhapis gracilis, 7.85% +/- 2.64% for Sabal minor, 9.20% +/- 1.35% for Chamaedorea cataractarum, and 12.42% +/- 1.78% for Chamaedorea brachypoda. The monthly changes of gross caloric value were different for Chamaerops humilis, Rhapis gracilis and Sabal minor, but similar to each other for Chamaedorea cataractarum and Chamaedorea brachypoda, and the annual average gross caloric value of the five shrubby species was 20.50 +/- 0.32 kJ x g(-1) for Chamaerops humilis, 20.04 +/- 0.50 kJ x g(-1) for Rhapis gracilis, 20.21 +/- 0.68 kJ x g(-1) for Sabal minor, 20.52 +/- 0.48 kJ x g(-1) for Chamaedorea cataractarum and 18.90 +/- 0.47 kJ x g(-1) for Chamaedorea brachypoda. The gross caloric values were correlated remarkably with ash contents for Chamaedorea cataractarum and Sabal minor (P < 0.05), but there was no significant correlation between gross caloric values and ash contents for other three species (P > 0.05). Rhapis gracilis and Sabal minor, and Chamaedorea cataractarum and Chamaedorea brachypoda had similar monthly changes in ash free caloric values, respectively. The average ash free caloric value of the five shrubby species was 21.55 +/- 0.53 kJ x g(-1) for Chamaerops humilis, 21.87 +/- 0.46 kJ x g(-1) for Rhapis gracilis, 21.84 +/- 0.53 kJ x g(-1) for Sabal minor, 22.60 +/- 0.81 kJ x g(-1) for Chamaedorea cataractarum, and 21.59 +/- 0.63 kJ x g(-1) for Chamaedorea brachypoda. Chamaedorea cataractarum had a higher ash free caloric value than other four species (P < 0.05), and the ash free caloric values of Chamaerops humilis, Rhapis gracilis, Sabal minor and Chamaedorea brachypoda were similar, the differences being not significant by t test (P > 0.05).