Advances on Thermally Conductive Epoxy-Based Composites as Electronic Packaging Underfill Materials-A Review.

The integrated circuits industry has been continuously producing microelectronic components with ever higher integration level, packaging density, and power density, which demand more stringent requirements for heat dissipation. Electronic packaging materials are used to pack these microelectronic components together, help to dissipate heat, redistribute stresses, and protect the whole system from the environment. They serve an important role in ensuring the performance and reliability of the electronic devices.

Fast-Response Bioinspired Near-Infrared Light-Driven Soft Robot Based on Two-Stage Deformation.

Herein, we report a remotely controlled soft robot employing a photoresponsive nanocomposite synthesized from liquid crystal elastomers (LCEs), high elastic form-stable phase change polymer (HEPCP), and multiwalled carbon nanotubes (MWCNTs). Possessing a two-stage deformation upon exposure to near-infrared (NIR) light, the LCE/HEPCP/MWCNT (LHM) nanocomposite allows the soft robot to exhibit an obvious, fast, and reversible shape change with low detection limitations. In addition to the deformation and bending of the LCE molecular chains itself, the HEPCP in the composite material can also be triggered by a reversible solid-liquid transition due to the temperature rise caused by MWCNTs, which further promotes the change of the LCE.

Limbal Bio-Engineered Tissue Employing 3D Nanofiber-Aerogel Scaffold to Facilitate LSCs Growth and Migration.

Constrained by the existing scaffold inability to mimic limbal niche, limbal bio-engineered tissue constructed in vitro is challenging to be widely used in clinical practice. Here, a 3D nanofiber-aerogel scaffold is fabricated by employing thermal cross-linking electrospinned film polycaprolactone (PCL) and gelatin (GEL) as the precursor. Benefiting from the cross-linked (160 °C, vacuum) structure, the homogenized and lyophilized 3D nanofiber-aerogel scaffold with preferable mechanical strength is capable of refraining the volume collapse in humid vitro.

Scalable Manufacture of High-Performance Battery Electrodes Enabled by a Template-Free Method.

Ion transport kinetics is identified as the major challenge of thick electrode design for high-energy-density lithium-ion batteries. The introduction of vertically-oriented structure pores, which provide fast transport pathways for Li , can maximize the rate-performance of electrodes while holding a high energy density. To overcome the harsh manufacturing requirements of traditional template-based methods for the oriented-pore electrodes, a template-free strategy is developed to meet the large-scale fabrication demand, in which controllable oriented microchannels are facilely constructed by vertically aggregated bubbles generated from thermal decomposition.

Nanoporous PVDF Hollow Fiber Employed Piezo-Tribo Nanogenerator for Effective Acoustic Harvesting.

Restricted by the inherent property of low power density, acoustic energy can hardly be effectively captured by conventional piezo- or triboelectric nanogenerators for powering miniature electronics. Herein, a novel piezo-tribo hybrid nanogenerator employing nanoporous polyvinylidene fluoride (PVDF) hollow fiber and polydimethylsiloxane (PDMS) valve, which can mimic the eardrum, has been advocated for efficient acoustic harvesting. The nanoporous, hollow, and valve structure design, together with the effective combination of piezo- and triboelectricity, make the nanoporous PVDF hollow fiber and PDMS valve based acoustic harvester (PHVAH) a promising candidate for acoustic-electric conversion.

Self-Powered Infrared-Responsive Electronic Skin Employing Piezoelectric Nanofiber Nanocomposites Driven by Microphase Transition.

Infrared light (IR) detection principles limited by poor photoresponsivity and sparse photogenerated carrier make them impossible to directly applied in flexible IR sensing field attributed to low π-π conjugation effect, thick P-N junction, and harsh band gap, of which IR self-powered electronic skin (e-skin) strongly relies on the essential property of exotic photosensitive-exciting materials, hardly any flexible organic polymer or nanocomposites. Here, an innovative IR self-powered principle is reported that outstanding piezoelectric effect of poly(vinylidene fluoride) nanofibers (PVDF NFs) is driven by microcrystals' volume expansion caused by the solid-solid phase transition of PVDF/multiwalled carbon nanotubes (MWCNTs)/highly elastic phase change polymer (HEPCP) (PMH) nanocomposites due to MWCNT's excellent IR photoabsorption and thermal conversion capabilities. A flexible IR-sensitive nanocomposite is successfully developed employing PVDF/HEPCP NFs as the framework of a three-dimensional network structure wrapped by the MWCNT/HEPCP nanocomposite.

High-strength cellulose films obtained by the combined action of shear force and surface selective dissolution.

Cellulose is a promising and advantageous material because it is low-cost, abundant and biodegradable. Nonetheless, dealing with this material is extremely challenging because cellulose cannot dissolve in most solvents or melt at any temperature or pressure in the air owing to strong hydrogen-bonding networks. In this work, a surface selective dissolution with shear force process was proposed to prepare cellulose films with high strength from microcrystalline cellulose powders.

Formability and Failure Mechanisms of Woven CF/PEEK Composite Sheet in Solid-State Thermoforming.

In this study, the formability of woven carbon-fiber (CF)-reinforced polyether-ether-ketone (PEEK) composite sheets in the solid-state thermoforming process were investigated, and the failure mechanisms were discussed. The formability of the woven CF/PEEK sheets were analyzed using flexural tests, Erichsen test, and microscopic observation. The results show that the formability of CF/PEEK sheets significantly increases as the temperature rises from 165 to 325 °C, and slightly decreases as the deformation speed rises from 2 to 120 mm/min.

Flexural Behavior and Fracture Mechanisms of Short Carbon Fiber Reinforced Polyether-Ether-Ketone Composites at Various Ambient Temperatures.

In this study, the flexural behavior and fracture mechanisms of short carbon fiber reinforced polyether-ether-ketone (SCFR/PEEK) composites at various ambient temperatures were investigated. First, the crystallinity and glass transition temperature () of PEEK and SCFR/PEEK were analyzed by differential scanning calorimetry analysis and dynamic mechanical analysis tests, respectively. The addition of SCFs increases the but does not change the crystallinity of the PEEK matrix.

[Clinical analysis of reoperation for recurrence thyroid carcinoma in 87 cases].

Objective: To explore the cause and the methods of reoperation for recurrent thyroid carcinoma.

Method: The clinicopathologic data of 87 cases were retrospectively analyzed. The diagnosis on recurrent thyroid carcinoma were confirmed after reoperative pathology.

[Significance of the expression of P53 protein and P21WAF1 protein in the gastric carcinoma tissues associated with Epstein-Barr virus (EBV) infections].

Background: To study the difference in gene expression between the EBV associated gastric carcinoma (EBVaGC) tissues. To explore the mechanism of gastric carcinoma pathogenesis initiated by EBV.

Methods: In situ hybridization was used to study the frequencies of EBV small RNA expression in 155 cases of gastric carcinoma tissues.