An Integrative Loss Function Approach to Multi‐Response Optimization

Loss function approach is effective for multi‐response optimization. However, previous loss function approaches ignore the dispersion performance of squared error loss and model uncertainty. In this paper, a weighted loss function is proposed to simultaneously consider the location and dispersion performances of squared error loss to optimize correlated multiple responses with model uncertainty. We propose an approach to minimize the weighted loss function under the constraint that the confidence intervals of future predictions for the multiple responses should be contained in specification limits of the responses. An example is illustrated to verify the effectiveness of the proposed method. The results show that the proposed method can achieve reliable optimal operating condition under model uncertainty. Copyright © 2013 John Wiley & Sons, Ltd.     

DNA/Tannic Acid Hybrid Gel Exhibiting Biodegradability,Extensibility, Tissue Adhesiveness,and Hemostatic Ability

DNA has emerged as a novel material in many areas of materials science due to its programmability. Especially, DNA hydrogels have been studied to incorporate new functions into gels. To date, only a few methods have been developed for fabricating DNA hydrogels, such as the use of complementary sequences or covalent bond. Herein, it is demonstrated that one of the most well‐known plant‐derived polyphenols, tannic acid (TA), can form a DNA hydrogel which is named TNA hydrogel ( T A + D NA ). TA plays a role as a “molecular glue” by a new mode of action reversibly connecting between phosphodiester bonds, which is different from the crosslinking utilizing complementary sequences. TA intrinsically degrades due to ester bonds connecting between pyrogallol groups, causing a degradable DNA hydrogel. Furthermore, TNA gel is multifunctional in that the gel is extensible upon pulling and adhesive to tissues because of the rich polyphenol groups in TA (ten phenols per TA). Unexpectedly, TNA gel exhibits superior in vivo hemostatic ability that can be useful for biomedical applications. This new DNA hydrogel preparation method represents a new technique for fabricating a large amount of DNA‐based hemostatic hydrogel without chemically modifying DNA or requiring the crosslinking by complementary sequences.     

A Surface Tailoring Method of Ultrathin Polymer Gate Dielectrics for Organic Transistors: Improved Device Performance and the Thermal Stability Thereof

Tailoring the surface of the dielectric layer is of critical importance to form a good interface with the following channel layer for organic thin film transistors (OTFTs). Here, a simple surface treatment method is applied onto an ultrathin (<15 nm) organosilicon‐based dielectric layer via the initiated chemical vapor deposition (iCVD) to make it compatible with organic semiconductors without degrading its insulating property. A molecular‐thin oxide capping layer is formed on a 15 nm thick poly(1,3,5‐trimetyl‐1,3,5‐trivinyl cyclotrisiloxane) (pV3D3) by a brief oxygen plasma treatment. The capping layer greatly enhances the thermal stability of the dielectrics, without degrading the original mechanical flexibility and insulating performance of the dielectrics. Moreover, the surface silanol functionalities formed by the plasma treatment can also be utilized for the surface modification with silane compounds. The surface‐modified dielectrics are applied to fabricate low‐voltage operating (<5 V) pentacene‐based OTFTs. The highest field‐effect mobility of the device with the surface‐treated 15 nm thick pV3D3 is 0.59 cm² V^?1 s^?1, which is improved up to two times compared to the TFT with the pristine pV3D3. It is believed that the simple surface treatment method can widely extend the applicability of the highly robust, ultrathin, and flexible pV3D3 gate dielectrics to design the surface of the dielectrics to match well various kinds of organic semiconductors.     

High‐Performance Transition Metal Dichalcogenide Photodetectors Enhanced by Self‐Assembled Monolayer Doping

Most doping research into transition metal dichalcogenides (TMDs) has been mainly focused on the improvement of electronic device performance. Here, the effect of self‐assembled monolayer (SAM)‐based doping on the performance of WSe₂‐ and MoS₂‐based transistors and photodetectors is investigated. The achieved doping concentrations are ≈1.4 × 10¹¹ for octadecyltrichlorosilane (OTS) p‐doping and ≈10¹¹ for aminopropyltriethoxysilane (APTES) n‐doping (nondegenerate). Using this SAM doping technique, the field‐effect mobility is increased from 32.58 to 168.9 cm² V^?1 s in OTS/WSe₂ transistors and from 28.75 to 142.2 cm² V^?1 s in APTES/MoS₂ transistors. For the photodetectors, the responsivity is improved by a factor of ≈28.2 (from 517.2 to 1.45 × 10⁴ A W^?1) in the OTS/WSe₂ devices and by a factor of ≈26.4 (from 219 to 5.75 × 10³ A W^?1) in the APTES/MoS₂ devices. The enhanced photoresponsivity values are much higher than that of the previously reported TMD photodetectors. The detectivity enhancement is ≈26.6‐fold in the OTS/WSe₂ devices and ≈24.5‐fold in the APTES/MoS₂ devices and is caused by the increased photocurrent and maintained dark current after doping. The optoelectronic performance is also investigated with different optical powers and the air‐exposure times. This doping study performed on TMD devices will play a significant role for optimizing the performance of future TMD‐based electronic/optoelectronic applications.     

Suction performance improvement of an annular jet pump by J-groove passage shape optimization

Journal of Mechanical Science and Technology - Jet pumps are special-purpose pumps without moving and rotating parts. The annular jet pump (AJP) is preferred for goods transportation over the...