Periodic Reporting for period 1 - WEARSENSNANO (Continuous monitoring of hypothermia in elderly people by the novel integrated wearable sensor system based on cellulose hydrogel and metallic nanowires)
Okres sprawozdawczy: 2021-06-01 do 2023-05-31
The European population is experiencing a continuous increase in average age, with the proportion of individuals aged 65 and above projected to rise from 21% in 2019 to 30% by 2050. This demographic trend carries significant social implications, particularly for Europe's future economy. Ageing poses a heightened risk of hypothermia, a condition where the body loses heat faster than it can generate, resulting in a potentially dangerous decrease in body temperature (<35°C). Manifestations of hypothermia encompass cold skin, muscle rigidity, shivering, unconsciousness, slow and shallow breathing, and changes in heart activity. To enable early detection of hypothermia, continuous monitoring of various physiological parameters, such as Electrocardiogram (ECG) signals, skin temperature, and muscle activities, is crucial. Nonetheless, several challenges exist in implementing such monitoring systems. Firstly, the need for rigid circuit boards and bulky power supplies to capture electrical signals from the body requires adhesion to the skin using adhesive tape and mechanical clamps. Secondly, this monitoring system necessitates the presence of a nurse or family member to provide dedicated attention or keep the patient in a hospital or specialized care facility. To address these issues, the proposed solution aims to utilize wearable sensors capable of measuring ECG signals, skin temperature, and muscle activities through pressure and temperature sensors, respectively. These wearable sensors are designed to be ultrathin, lightweight, flexible, stretchable, and conformable, facilitating unobtrusive and comfortable monitoring. By enabling care for elderly individuals within private homes using wearable sensors, this solution opens new possibilities for human-activity monitoring and personal healthcare. The current market for wearable sensors detecting pressure, temperature, and strain is substantial, estimated to reach approximately 10 billion USD by 2019, accompanied by a surge in patents, companies, and products in this domain. Main target of the project was to enable highly sensitive wearable integrated capacitive type pressure sensors and resistive type temperature sensor systems for real time human motion detection and body temperature. Our objective was to fabricate the sensors with low-cost materials, sensitive dielectric material, skin friendly natural flexible substrate as well as uncomplicated processes.
In this project, a wearable integrated sensor was developed with the capability to detect muscle activities and body temperature. The components of the pressure sensor, comprising the dielectric layer, substrate, and electrode materials, were manufactured using biomass-sourced, biodegradable, and flexible materials. Specifically, pectin aerogel, carbonized cellulose aerogel particles, and cellulose were employed as the dielectric layer, electrode material, and substrate, respectively. This innovative approach aimed to replace non-biodegradable materials with environmentally friendly alternatives, addressing concerns related to environmental pollution. The sensor exhibited remarkable properties, including a wide range of pressure sensing (10 Pa - 500 kPa), a sensitivity of 300 MPa-1 in the subtle pressure regime, dynamic durability over 10,000 cycles, rapid response time (98 ms), and swift recovery time (164 ms). Additionally, the sensor demonstrated effective performance in sensing joint activities such as knee, elbow, and finger bending, as well as muscle activities like smiling, swallowing, and bicep contraction. Moreover, a temperature sensor was fabricated using inkjet printing of silver interdigitated electrodes on a flexible cellulose substrate, followed by blade coating of functional materials such as Mxenes, carbon nanotubes (CNTs), and graphene. The temperature sensor exhibited desirable properties, including an application range of 20-100 oC, a sensitivity of 1%/oC, a response time of 100 ms, a recovery time of 150 ms, dynamic durability of 100 cycles, and effective temperature mapping capabilities with a 3x3 sensor matrix. Furthermore, the integration of the pressure and temperature sensors resulted in the creation of an integrated wearable sensor, which was effectively utilized for human motion detection and body temperature measurement.
The sensors developed within this project exhibit vast potential for a range of applications, encompassing cardiovascular health monitoring, breast cancer detection, cognitive state assessment, heart failure management, respiratory disorder tracking, sleep apnea-hypopnea syndrome identification, Parkinson's disease monitoring, facial expression analysis, and skin sclerosis evaluation. These extensive possibilities hold significant implications, particularly in the realm of health product development. Furthermore, the innovative concepts and ideas originating from this project possess considerable relevance in other advanced research domains, including smart prosthetics, advanced robot skins, e-skin, and intelligent human-machine interactions. Consequently, the researcher envisions numerous prospects for future scientific endeavors and start-up funding, including esteemed grants like ERC-CoG, participation in Eurostars and EUR FET programs, initiatives at the national level, and involvement in Nanotechnologies programs.