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Smart hydrogels for biomedical applications are highly researched materials. However, integrating them into a device for implantation is difficult. This paper investigates an integrated delivery device designed to deliver an electro-responsive hydrogel to a target location inside a blood vessel with the purpose of creating an occlusion. The paper describes the synthesis and characterization of a Pluronic/methacrylic acid sodium salt electro-responsive hydrogel. Application of an electrical bias decelerates the expansion of the hydrogel. An integrated delivery system was manufactured to deliver the hydrogel to the target location in the body. Ex vivo and in vivo experiments in the carotid artery of sheep were used to validate the concept. The hydrogel was able to completely occlude the blood vessel reducing the blood flow from 245 to 0 ml/min after implantation. Ex vivo experiments showed that the hydrogel was able to withstand physiological blood pressures of > 270 mm·Hg without dislodgement. The results showed that the electro-responsive hydrogel used in this paper can be used to create a long-term occlusion in a blood vessel without any apparent side effects. The delivery system developed is a promising device for the delivery of electro-responsive hydrogels. [ABSTRACT FROM PUBLISHER]

Wide-bandgap materials such as silicon carbide enable power electronics to face increasing demands for greater power density and high-temperature capability at the chip level. However, new packaging solutions have yet to be found to replace Pb solders in high-temperature applications. In this paper, the applicability of electrodeposited Ag thin film as a novel high-temperature die-attach material to connect power chips to direct-bonded copper substrates is investigated. Ag films were obtained by electrochemical deposition on the backmetallization of Si chips. The joint was then produced by thermocompression bonding at 350^\circC with a 40-N force applied for 10 min in air. A die shear strength of 1.70 MPa (twice the MIL standard) was achieved. The assembly demonstrated satisfactory resistance to thermomechanical fatigue when subjected to thermal aging and thermal cycling tests in high-temperature environments. The proposed bonding technology is thus a suitable solution for the provision of strong and reliable joints for power devices which have to operate in extreme temperature conditions (>200^\circC). [ABSTRACT FROM AUTHOR]

Presents information on a study which described a power cycling in-test monitoring system to assess the reliability of different lead-free surface mount assemblies. Experimental details; Results and discussion; Conclusions.