Development of Li0.33La0.56TiO3 based Solid Electrolyte Materials

As the increasing need for electronic products like smartphones, lithium-ion batteries have been a vital topic in this era. For developing batteries with higher electrochemical performance and safety, solid electrolytes play a significant role in increasing safety owing to less risk of electrolytes leakage and a wider electrochemical window for higher energy density. Among various materials, inorganic ceramic solid electrolytes lead the intention because of their high electrochemical performance, such as ionic conductivity. However, compared to traditional liquid electrolytes, the ionic conductivity of ceramic solid electrolytes is still below current requirements. To optimize ionic conductivity, strategies of decreasing grain and grain boundary resistance are required. In this thesis, three different strategies for optimizing Li0.33La0.56TiO3 materials’ ionic conductivity were developed. Lithium lanthanum titanate (LLTO) powder was prepared using a modified sol-gel process with three chelating agents. After initial structural characteristics, LLTO pellets were prepared by spark plasma sintering. To investigate alternation of grain and grain boundary resistance of the LLTO, Ag dopants were introduced to LLTO, and composite pellets of LLTO and silver nanowires were also fabricated. The LLTO synthesized by acetic acid was found to have the strongest intensity, minor impurity, and the biggest crystallite size from XRD patterns and Rietveld refinement compared with LLTO synthesized by citric acid and a mix of citric acid and glucose. According to the XRD patterns, Ag doping of LLTO (Li0.33-xLa0.56AgxTiO3) was positively proved by shifting away from the original target Li0.33La0.56TiO3. The composite pellet (LLTO/AgNWs) was successfully fabricated by spark plasma sintering, and the LLTO/AgNWs pellet showed a more apparent grain boundary from the SEM image. The modified sol-gel method has been proved that it is an efficient way to synthesize LLTO with low reaction temperature and short reaction time compared with the traditional physical reaction method. The pure LLTO pellet was fabricated with a 10(-4) S/cm grain conductivity via spark plasma sintering (SPS). Due to successful chemical composition alteration, the Ag-doped LLTO pellet reached higher grain conductivity by 2 *10(-5) S/cm than the pure LLTO pellet. The composite LLTO/AgNWs pellet was also efficiently fabricated through SPS

Optimization-Based Peptide Mass Fingerprinting for Protein Mixture Identification

*Motivation:* In current proteome research, peptide sequencing is probably the most widely used method for protein mixture identification. However, this peptide-centric method has its own disadvantages such as the immense volume of tandem Mass Spectrometry (MS) data for sequencing peptides. With the fast development of technology, it is possible to investigate other alternative techniques. Peptide Mass Fingerprinting (PMF) has been widely used to identify single purified proteins for more than 15 years. Unfortunately, this technique is less accurate than peptide sequencing method and cannot handle protein mixtures, which hampers the widespread use of PMF technique. If we can remove these limitations, PMF will become a useful tool in protein mixture identification. 
*Results:* We first formulate the problem of PMF protein mixture identification as an optimization problem. Then, we show that the use of some simple heuristics enables us to find good solutions. As a result, we obtain much better identification results than previous methods. Moreover, the result on real MS data can be comparable with that of the peptide sequencing method. Through a comprehensive simulation study, we identify a set of limiting factors that hinder the performance of PMF method in protein mixtures. We argue that it is feasible to remove these limitations and PMF can be a powerful tool in the analysis of protein mixtures

Flow-based Intrinsic Curiosity Module

In this paper, we focus on a prediction-based novelty estimation strategy upon the deep reinforcement learning (DRL) framework, and present a flow-based intrinsic curiosity module (FICM) to exploit the prediction errors from optical flow estimation as exploration bonuses. We propose the concept of leveraging motion features captured between consecutive observations to evaluate the novelty of observations in an environment. FICM encourages a DRL agent to explore observations with unfamiliar motion features, and requires only two consecutive frames to obtain sufficient information when estimating the novelty. We evaluate our method and compare it with a number of existing methods on multiple benchmark environments, including Atari games, Super Mario Bros., and ViZDoom. We demonstrate that FICM is favorable to tasks or environments featuring moving objects, which allow FICM to utilize the motion features between consecutive observations. We further ablatively analyze the encoding efficiency of FICM, and discuss its applicable domains comprehensively.Comment: The SOLE copyright holder is IJCAI (International Joint Conferences on Artificial Intelligence), all rights reserved. The link is provided as follows: https://www.ijcai.org/Proceedings/2020/28

Q-enhanced fold-and-bond MEMS inductors

This work presents a novel coil fabrication technology to enhance quality factor (Q factor) of microfabricated inductors for implanted medical wireless sensing and data/power transfer applications. Using parylene as a flexible thin-film device substrate, a post-microfabrication substrate folding-and-bonding method is developed to effectively increase the metal thickness of the surface-micromachined inductors, resulting in their lower self-resistance so their higher quality factor. One-fold-and-bond coils are successfully demonstrated as an example to verify the feasibility of the fabrication technology with measurement results in good agreements with device simulation. Depending on target specifications, multiple substrate folding-and-bonding can be extensively implemented to facilitate further improved electrical characteristics of the coils from single fabrication batch. Such Q-enhanced inductors can be broadly utilized with great potentials in flexible integrated wireless devices/systems for intraocular prostheses and other biomedical implants