PACS. 05.45.-a Nonlinear dynamics and nonlinear dynamic systems - 45.70.Vn Granular models of complex systems; traffic flow - 89.40.+k Transportation,

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In recent years, wearable technologies have attracted great attention in physical and chemical sensing applications. Wearable pressure sensors with high sensitivity in low pressure range (<10 kPa) allow touch detection for human-computer interaction and the development of artificial hands for handling objects. Conversely, pressure sensors that perform in a high pressure range (up to 100 kPa), can be used to monitor the foot pressure distribution, the hand stress during movements of heavy weights or to evaluate the cyclist’s pressure pattern on a bicycle saddle. Recently, we developed a fully textile pressure sensor based on a conductive polymer, with simple fabrication and scalable features. In this paper, we intend to provide an extensive description on how the mechanical properties of several fabrics and different piezoresistive ink formulation may have an impact in the sensor’s response during a dynamic operation mode. These results highlight the complexity of the system due to the presence of various parameters such as the fabric used, the conductive polymer solution, the operation mode and the desired pressure range. Furthermore, this work can lead to a protocol for new improvements and optimizations useful for adapting textile pressure sensors to a large variety of applications.

The pandemic triggered by the SARS-CoV-2 virus has produced worldwide interruptions of face-to-face teaching activity in both schools and universities. In Italy, the quarantine began in the second half of February 2020 and lasted for all the second semester of lectures. The University of Bologna, where all the authors of the present article are based, developed and activated several interfaces necessary to efficiently deliver online teaching courses with the utmost speed. The framework used by the authors is based on a common platform, Microsoft TEAMS, available to all teachers at Bologna University.

An automatic vibrating reed apparatus for internal friction and elastic modulus measurements in solids is described. The apparatus is equipped with a resistive heater for measurements up to 1400 K. A magnetic field (up to 250 kAt/m) is also available in the 300–1000 K range. Measurements as a function of temperature and/or magnetic field can be easily carried out. Data acquisition is controlled by a computer and originally written software allows automatic measurements and real time data analysis offering a user-friendly interface. The acquisition rate is nearly two orders of magnitude faster than that achieved manually. The use of the analyzer is straightforward and does not require a prolonged training of particularly skillful personnel.

Recent studies in the field of safety in the workplace have focused on developing new sensors and procedures to detect and monitor body stress due to repeated or highly stressful movements that, in the long term, could lead to painful traumas or accidents. Today, the common method used to evaluate risk activities is based on evaluations that are subjective or supported by difficult and timeconsuming video analysis. However, recent developments in wearable sensors, in particular pressure sensors, allow for innovative alternatives. The main requirements of wearable pressure sensors are good wearability, allowing natural movements and a sensor response in a broad range of pressure to allow a large variety of possible activities to be monitored. In this paper, we report on a new promising class of textile pressure sensors based on the employment of a conductive polymer that can be easily deposited directly on the fabric, for example, to fabricate sensorized gloves to monitor hand stress during manual activity. The main advantages of the proposed technology comprise the possibility of selectively tuning the pressure response range, adapting it to different applications by changing the formulation of the conductive polymer while leaving the same device architecture and structures. We deposit and characterize the active sensing layer, analyze the pressure sensor response and propose an interpretation of the obtained results based on piezoresistive phenomena. We identify three different contributions to the sensor output, related to the macroscale, microscale and nanoscale, respectively. Finally, we describe the production of sensorized textile gloves with fully textile pressure sensors that are comfortable, reproducible, low cost and easily tunable in pressure range response.

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