Gecko gaskets for self-sealing and high-strength reversible bonding of microfluidics.

We report in this work a novel reversible bonding technique for elastomeric microfluidic devices by integrating gecko-inspired dry adhesives with microfluidic channels which greatly enhances the bonding strength of reversibly sealed channels. The concept is applicable to nearly any elastomer and can be used to bond against any smooth surface which allows for van der Waals interactions. It does not require any solvents or glues or sources for plasma activation or thermal-compressive loading to aid the bonding process and is achievable at zero extra cost. We also demonstrate a quick fabrication technique involving soft master thermo-compressive molding of these microfluidic devices with thermoplastic elastomers. The resultant devices can be used for both pressure driven and non-pressure driven flows. We report the maximum contained pressure of these devices manufactured from two grades of styrene ethylene butylene styrene (SEBS) by conducting a burst pressure test with various substrates.

An analysis of some variables influencing the effectiveness of reprimands.

Although several studies have shown that social reprimands can function as punishers, no study reported to data has isolated any of the factors influencing reprimand efficacy. Three experiments were conducted to investigate several factors. Experiment 1 used an alternating treatments design and was conducted on two elementary school boys, one of whom was in a special education class. Results showed that verbal reprimands delivered with eye contact and firm grasp of the student's shoulders reduced disruptive behavior to a greater extent than did verbal reprimands delivered without eye contact and grasp. Both types of reprimand were more effective than a baseline condition during which disruptive behavior was ignored. Experiment 2 also used an alternating treatments design and was conducted on one elementary school boy. Results demonstrated that reprimands delivered from one meter away were considerably more effective than reprimands delivered from seven meters away. Experiment 3 used a reversal design and was conducted on two pairs of elementary school children, one a pair of boys and the other a pair of girls. Results demonstrated that reprimands delivered to just one member of the pair reduced the disruptive behavior of both members of the pair. Thus, the effects of reprimands "spilled" over to nonreprimanded students.