Investigation on the Use of the PE873 Conductive Ink for Surface EMG Measurements

Nowadays, wearable devices are part of everyone’s life and their popularity is constantly increasing. With diverse applications, spanning from healthcare to fitness tracking, more and more wearable devices are being developed which can send and receive information in real-time. To date, electric cables represent the most stable form of communication in terms of reliability and resistance. However, for wearable systems, cables restrict movement and introduce additional noise and movement artefacts on wearable sensing systems. Wireless devices, on the other hand, can be comparatively complicated in design, manufacturing and use. A possible strategy, to improve communications in wearable systems, is the adoption of conductive inks able to conduct electrical signals, these can be printed on fabric without the movement restriction normally associated with traditional wired systems. The use of such conductive inks in wearable sensors may, therefore, lead to a more comfortable method of monitoring health data (heart rate, muscle contraction etc.) throughout the day. In this paper, the properties of the promising conductive ink PE873 (manufactured by DuPont) are tested and analysed. The conductive ink electrical properties are studied in relation to stretching, folding and washing tests. The electrical performance of the ink printed onto the selected fabric is assessed and presented. Furthermore, an optimized printing procedure, aiming at improving the connection performances, is suggested and the development of a novel system able to read muscle contractions, based on PE873, is demonstrated, thus showing that this conductive ink is a promising solution for stretchable electrical connections in the wearable field

A multi-sensors wearable system for remote assessment of physiotherapy exercises during ACL rehabilitation

In this paper, the challenges associated with the design of a novel multi-sensor wearable system for the objective assessment of exercises during lower-limbs rehabilitation are described. The overall system architecture is defined, and finally both the implemented hardware and software platforms are illustrated in detail. Multiple sensing technologies are adopted including motion data, electromyography measurements, and muscle electro-stimulation. The software stack provides guidance to the users throughout the rehabilitation therapy sessions, and allows clinicians to access the data collected remotely in real-time thus supporting their clinical evaluation. Finally, preliminary results of the comparison between the knee joint angle estimated by the developed system against a gold-standard inertial-based system are provided showing promising results for future validation

Design of a multi-sensors wearable platform for remote monitoring of knee rehabilitation

Smart wearables are a promising tool for the objective and quantifiable monitoring of patients' capabilities during remote at-home assessments. A novel platform for the remote assessment of patients undergoing knee rehabilitation has been presented in this paper, SKYRE. The challenges associated with the design of the SKYRE platform are described. The platform consists of a multi-sensor wearable garment and an associated ICT architecture, with the aim of capturing real-time objective assessment of physical rehabilitation exercises and support clinicians in their decision-making process as well as provide guidance to the end-users so as to increase their awareness and compliance. The overall system architecture is defined based on usersâ requirements and industrial design, and both hardware and software platforms have been thoroughly discussed in detail, including electronic design, textile integration, prototyping process, and firmware development, as well as the mobile application and web portal implementation. Multiple sensing technologies are adopted, including motion capture, electromyography measurements, and muscle electro-stimulation. The developed system, SKYRE, meets the end-usersâ requirements, and the validation shows that the system presents results comparable to gold-standard technologies. SKYRE therefore might represent a valid alternative for patients and clinicians willing to perform a remote objective assessment of the rehabilitation process following knee surgery

Thermal characterization of direct wafer bonded Si-on-SiC

Direct bonded Si-on-SiC is an interesting alternative to silicon-on-insulator (SOI) for improved thermal management in power conversion and radio frequency applications in space. We have used transient thermoreflectance and finite element simulations to characterize the thermal properties of direct bonded Si-on-4H–SiC samples, utilizing a hydrophobic and hydrophilic bonding process. In both instances, the interface has good thermal properties resulting in TBReff values of 6 + 4/−2 m2 K GW−1 (hydrophobic) and 9 + 3/−2 m2 K GW−1 (hydrophilic). Two-dimensional finite element simulations for an equivalent MOSFET showed the significant thermal benefit of using Si-on-SiC over SOI. In these simulations, a MOSFET with a 200 nm thick, 42 μm wide Si drift region was recreated on a SOI structure (2 μm buried oxide) and on the Si-on-SiC material characterized here. At 5 W mm−1 power dissipation, the Si-on-SiC was shown to result in a >60% decrease in temperature rise compared to the SOI structure

Influence of free radical surface activation on Si/SiC heterogeneous integration by direct wafer bonding

In this study, a surface activated bonding method using remote plasma is applied to realize the direct wafer bonding of Si and SiC. A comparison of different surface treatments is reported. Hydrophilic and hydrophobic wafers have been exposed to in-situ argon and nitrogen radicals generated by remote plasma for surface activation before bonding. A comparison of the bonding yield and surface condition has been conducted and analyzed as a function of the surface treatments. It has been shown that N2 plasma leads to the highest yield of > 97 %, strongest bond of > 360 N and interfacial layer (IL) thickness of ~1.5 nm

Wearable textile-based device for human lower-limbs kinematics and muscle activity sensing

Lower-limbs kinematics and muscle electrical activity are typically adopted as feedback during rehabilitation sessions or athletes training to provide patients’ progress evaluation or athletic performance information. However, the complexity of motion tracking and surface electromyography (sEMG) systems limits the use of such technologies to laboratory settings and requires special training and expertise to carry out accurate measurements. This paper presents a new wearable textile-based muscle activity and motion sensing device for human lower-limbs, which is capable of recording and wirelessly transmitting sEMG data for several specific muscles as well as kinematic parameters, allowing outdoor and at-home use without direct supervision by non-expert users. In particular, this work is focused on the development and analysis of textile electrodes and garment design, as well as the definition of a proof-of-concept study for sEMG data recording. Obtained values were compared against average rectified values (ARV) recorded using a gold-standard conventional wireless sEMG system. Apart from one muscle (vastus medialis), the developed device showed overall promising results in the muscle activity sensing for lower-limbs, highlighting its possible use in the rehabilitation and sport performance fields. In addition, a washing test was conducted on the electrodes, where it was shown that the proposed textile electrodes maintained structural integrity and showed an acceptable level of electrical parameters deterioration when comparing pre and post washing characteristics

Ex-situ plasma doping of MoS2 thin films synthesised by thermally assisted conversion process: Simulations and experiment

Controllable doping of two-dimensional (2D) materials is one of the main research challenges associated with the practical realization of 2D semiconductors in hetero-and homo-junctions. We report that the selected-area treatment of MoS2 films with nitrogen plasma can modify the resistivity of the film. To identify the underlying physical mechanism responsible for such observation, we systematically investigated the transport properties of cTLM-patterned contacts on ~70nm non-intentionally doped (NID), p-and p-doped MoS 2 films before and after plasma exposure. Electrical characterization demonstrates that p-type doping of MoS2 is achieved by plasma-induced nitrogen doping. HR-TEM images confirm that no etching of the exposed film has occurred. Our experimental observations are supported by first principles atomic scale simulations suggesting the interaction of nitrogen with defects and vacancies in the poly-crystalline MoS2 films as the origin of doping mechanism. The results indicate low-power nitrogen plasma is an effective approach for ex-situ doping of MoS2

Integrated (epi)-Genomic Analyses Identify Subgroup-Specific Therapeutic Targets in CNS Rhabdoid Tumors

We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype

Integrated (epi)-Genomic Analyses Identify Subgroup-Specific Therapeutic Targets in CNS Rhabdoid Tumors

We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype