RESUMO
Soft actuators with the integration of facile preparation, rapid actuation rate, sophisticated motions, and precise control over deformation for application in complex devices are still highly desirable. Inspired by the aligned structures of moisture responsive pineal scales, an oil-triggered Janus actuator composed of a smooth hydrophobic surface and a superhydrophobic surface with aligned microchannels by simple laser etching was fabricated successfully, which can deform into various desirable shapes and recover to the original shape when triggered by oil and ethanol molecules. The aligned microchannel design causes different oil spread distances in the longitudinal and transverse directions, resulting in orientation-controlled bending and twisting with large-scale displacement. By changing the orientations of the patterned microchannels, one-dimensional folding deformation, twisting, rolling curling and object-inspired architectures can be facilely programmed. The reversible oil-triggered actuator will inspire more attractive applications such as in vivo surgery, biomimetic devices, energy harvesting systems and soft robotics.
RESUMO
Soft actuators have tremendous applications in diverse fields. Facile preparation, rapid actuation, and versatile actions are always pursued when developing new types of soft actuators. In this paper, we present a facile method integrating laser etching and mechanical cutting to prepare Janus actuators driven by oil. A Janus film with superhydrophobic and hydrophobic sides was fabricated successfully. By cutting the functional layer at the desired positions, a number of quintessential oil-driven soft devices were demonstrated. Furthermore, Janus actuators with surfaces of different wettabilities exhibited different swelling behaviors, and different media manifested different surface extensions; thus, these actuators are promising candidates for soft actuators and also realized on-off switchability between an oil/water mixture and ethanol. This study offers novel insight into the design of soft actuators, and this insight may be helpful for developing an oil-driven soft actuator that can be operated like a human finger to manipulate any object and extending stimuli-responsive applications for soft robotics.
RESUMO
BACKGROUND: The laparoscopic mini-gastric bypass is a newly emerged surgical procedure in recent years. Owe to safe and simple process and effective outcomes, laparoscopic mini-gastric bypass has quickly become one of the most popular procedures in some countries. The safety and effectiveness of laparoscopic mini-gastric bypass versus laparoscopic sleeve gastrectomy remain unclear. METHODS: A systematic literature search was performed in PubMed, Embase, Cochrane library from inception to May 20, 2017. The methodological quality of Randomized Controlled Trials and non-Randomized Controlled Trials were, respectively, assessed by Cochrane Collaboration's tool for assessing risk of bias and Newcastle-Ottawa scale. The meta-analysis was performed by RevMan 5.3 software. RESULTS: Patients receiving mini-gastric bypass had a lot of advantageous indexes than patients receiving sleeve gastrectomy, such as higher 1-year EWL% (excess weight loss), higher 5-year EWL%, higher T2DM remission rate, higher hypertension remission rate, higher obstructive sleep apnea (OSA) remission rate, lower osteoarthritis remission rate, lower leakage rate, lower overall late complications rate, higher ulcer rate, lower gastroesophageal reflux disease (GERD) rate, shorter hospital stay and lower revision rate. No significant statistical difference was observed on overall early complications rate, bleed rate, vomiting rate, anemia rate, and operation time between mini-gastric bypass and sleeve gastrectomy. CONCLUSION: Mini-gastric bypass is a simpler, safer, and more effective bariatric procedure than laparoscopic sleeve gastrectomy. Due to the biased data, small sample size and short follow-up time, our results may be unreliable. Large sample and multicenter RCT is needed to compare the effectiveness and safety between mini-gastric bypass and sleeve gastrectomy. Future study should also focus on bile reflux, remnant gastric cancer, and long term effectiveness of mini-gastric bypass.