Periodic Reporting for period 2 - BEWELL (Wearable sensors and actuators to monitor and promote physical and emotional wellbeing) Reporting period: 2020-10-01 to 2022-03-31 Summary of the context and overall objectives of the project BEWELL project is about developing integration and manufacturing technologies needed for smart skin patch and wrist-device wearable electronics sensing and actuating products. BEWELL project is also about demonstrating three different application use cases.Wearable electronics belongs to new age consumer electronics together with smartphones, gaming consoles and laptop/tablet computers. Key development focuses of the new devices are better human-machine interfaces, improved connectivity, user-friendly form factors and convenience of use. Internet of things, connected living, quantifed self and smart homes are identifed as the driving trends of this evolution among which especially the quantifed self is clearly driving the wearable electronics. Inside wearable electronics, wrist-worn devices have been the largest segment but body-worn and head-worn devices are expected to grow to similar sized segments. Intimate skin contact is necessary for reliable sensing and actuation based on sensor results during different levels of activity of the users. Controllable skin contact would be a further improvement in sensing applications. The purpose can be to replace or supplement visual messaging. Therefore, skin patches and associated technologies to enhance the user-device interface also in other types of products such as the wrist-worn ones are of special importance. In BEWELL, we have identified commercially relevant future skin-patch products to be demonstrated. We have also identified a set of critical and versatile technologies that need to be developed for scalable manufacturing and integrated to realize these future products. In particular, the BEWELL project aims to unleash the potential of flexible and wearable electronics for physical and emotional wellbeing by advanced integrated technology components made in Europe.The overall objectives are as follows.Demonstration of three different product use cases. Two use cases are skin patches and one use case is a wristband. The skin patches integrate (i) power from primary or secondary battery and a photovoltaic, (ii) visual indicator or display elements, (iii) a decoration layer, (iv) biosignal measurements such as bioimpedance, galvanic skin response, ECG and body temperature and (v) haptic user feedback. Application cases for the patches are in emotional sensing and skin health measurements. Haptic large-area actuator array integrated on flexible substrate together with organic multiplexing/addressing circuitry combined with IC and later thin-film driver electronics.Flexible haptics driver based on large-area thin-film IGZO technology will be developed to replace the IC chip of the previous objective on the controller layer in order to enhance flexibility and reduce system thickness and cost.Skin adhesion technology that provides adequate adhesion and the needed sensing and actuation contacts to the skin.Flexible Plastic injection moulding of the actuators and sensors.Flexible primary and rechargeable batteries optimized for the skin-patch use.Novel electro-active polymer solutions to optimize the comfort of wear.Integration technolofies to improve the flexibility and stretchability of the wearable solutions. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far New skin adhesives have been developed to match the application requirements of the patch products. The adhesives are tested as worn on skin. First rechargeable printable Li-ion battery based on PEO/LiTFSI membrane has been demonstrated. Cycling tests up to 150 cycles have been done.Solutions to integrate bare-die ASIC components on flexible and stretchable substrates have been tested.Flexible perovskite photovoltaic has been demonstrated for module efficiency of about 12 % and open-circuit voltage of about 7 V.Market analysis and use-case designs have been done and utilized in demonstrator specifications and design.Haptics array has been demonstrated on body.Thin-film flexible haptics IGZO driver was implemented and demonstrated.Flexible perovskite photovoltaic was demonstrated in circular form factor.Repositionable and changeable skin-electrode layer was developed. Functional decorative layer combined with LED display and the photovoltaic was developed.Technologies for printable rechargeable battery were developed.Integration of all the functionalities into a vertical skin-patch structure that minimizes the rigid area of electronics and uses stretchable skin-contacting electrode layer was demonstrated.On-body ECG measurements were demonstrated for the skin patch.Wrist device with multiple PPG detection locations was developed and demonstrated in LOPEC 2022 conference competition for publicly-funded demonstrators.Elastomer moulding process for the wrist device was developed. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Results now and expectation (impact):The first Flexible Perovskite Solar Cell with round-shape is generated specially for BEWELL to be integrated with other parts of full device in order to charge the battery in sun light as well as indoor light conditions. (New energy-autonomous wearable products also for low-light conditions possible.)First printed LIB having a quasi-solid electrolyte. First cycling tests successful already. Sealing can be used for other battery systems as well. (Same as above.)IGZO thin-film logic on flexible substrate interfacing between low-voltage silicon IC and flexible high-voltage OTFT electronics and haptics. (New level of flexible integration of complex products for wearable form factor.)A custom GSR mode was implemented in new version of an existing ASIC. It significantly improves the functionality of the ASIC, now having an additional read-out modality but keeping the footprint the same. (New applications.)Co-integration of haptics and OTFT. (Same as for IGZO)Use of low voltage flexible piezo actuators for haptic interaction with users. (New wearable functionalities.)Integration of haptics on fabrics. (New application field for haptics.)Skin patch that consist of a special adhesive that improves the wearability of the patch. (Better acceptance of products on market.)First integration of Functional Crystals with printed LED layer and printed Perovskite Solar Cell (PSC). (New user interfaces.)New or further optimized filter coatings for Functional Energy Crystals – allowing for charging of solar cells with high energy efficiency. (New level of integration possible.)Reliable electrical vias on TPU proven in stretch testing and used to implement a stretchable skin electrode layer of the skin patch. (New structural solutions towards stretchability.)Bare-die assembly on flexible substrate achieved for 100 um pitch. (Thinner and more flexible and stretchable products with better wearability.)Proof-of-concept for combination of bio-signal measurements (ECG and GSR) in different body locations: e.g. wrist, shoulder, chest. (New applications.) Final skin patch demonstrator Schematic stack structure of the skin patch Wrist device on body. Bending test for the battery Open circuit voltage measurement of decoration layer in the sun. Cycling profile of standard electrodes in a CR2032 coin cell with Freudenberg and developed PVdF sep Measurement results for flexible perovskite photovoltaic Skin-contact layer under testing PSC measurements at VTT Integrated skin patch on body for ECG measurement. Finger from right hand is touching the conductive Touch Crystal resistance measurement performed in Swarovski laboratory Wrist band concept.
