Soft material-enabled electronics can demonstrate extreme mechanical flexibility and stretchability. Such compliant, comfortable electronics allow continuous, long-term measurement of biopotentials on the skin. Manufacturing of the stretchable electronic devices is enabled by the recent development combining materials transfer printing and microfabrication. However, the existing method using inorganic materials and multi-layered polymers requires long material preparation time and expensive processing cost due to the requirement of microfabrication tools and complicated transfer printing steps. Here, this study develops a new fabrication method of soft electronics via a micro-replica-molding technique, which allows fast production, multiple use, and low cost by avoiding microfabrication and multiple transfer printing. The core materials, carbon nanomaterials integrated with soft elastomers, further reduces the entire production cost, compared to costly metals such as gold and silver, while offering mechanical compliance. Collectively, skin-wearable electrodes, designed by optimized materials and fabrication method enable a high-fidelity measurement of non-invasive electromyograms on the skin for advanced human-machine interface, targeting prosthesis.

A critical and important part of the medical diagnosis is the montioring of the biopotential signals. Patients are always connected to a bulky and mains-powered instrument. This not only restricts the mobility of the patients but also bring discomfort to them. Meanwhile, the measureing time can not last long thus affecting the effects of the diagnosis. Therefore, there is a high demand for low-power and small size factor ambulatory biopotential measurement systems. In addtion, the system can be configured for different biopotential applications.The ultimate goal is to implement a system that is both invisible and comfortable. The systems not onlyincrease the quality of life, but also sharply decrease the cost of healthcare delivery. In this paper, a continuously tunable gain and bandwidth analog front-end for ambulatory biopotential measurement systems is presented. The front-end circuit is capable of amplifying and conditioning different biopsignals. To optimize the power consumption and simplify the system architecture, the front-end only adopts two-stage amplifiers. In addition, careful design of the critical transistors eliminates the need of chopping circuits. The front-end is pure analog without interference from digital parts like chopping and switch capacitor circuits. The chip is fabricated under SMIC 0.18 μm CMOS process. The input-referred noise of the system is only 1.19 μVrms (0.48-2000Hz).Although the power consumption is only 32.1 μW under 3V voltage supply, test results show that the chip can successfully extract biopotential signals.

A low-cost circuit board design is presented, which in one embodiment is smaller than a credit card, for biopotential (EMG, ECG, or EEG) data acquisition, with a focus on EEG for brain-computer interface applications. The device combines signal conditioning, low-noise and high-resolution analog-to-digital conversion of biopotentials, user motion detection via accelerometer and gyroscope, user-programmable digital pre-processing, and data transmission via Bluetooth communications. The full development of the device to date is presented, spanning three embodiments. The device is presented both as a functional data acquisition system and as a template for further development based on its publicly-available schematics and computer-aided design (CAD) files. The design will be made available at the GitHub repository https://github.com/kellygs/eeg.

<p dir="ltr">A new class of bioplastics polymer materials synthesized from hemp-derived cannabinoids are demonstrated through a lifecycle approach. The poly(cannabinoid) material platform is utilized to develop application-specific polymers for the fabrication of electrocardiogram electrodes and on-skin heaters. A rigid homopolymer pCBD-adipate is synthesized to formulate conductive composite inks and a CBD/CBG block copolymer is developed as an adhesive. Inks are printed using the DIW process allowing for versatile and rapid prototyping of devices. ECG performance assessments yield comparable performance to conventional wet gel electrodes in ambient conditions, and improved performance in submerged testing. Heating devices are demonstrated for conformality by application to a joint, as well as self-regulating capabilities by controller-free joule heating. Following device applications, pCBD-adipate homopolymer conductive composite is used to demonstrate disposal routes of poly(cannabinoid)s through mechanical and chemical recycling. Mechanical recycling exhibits high conductivity over multiple cycles but notably diminishes. Chemical recycling achieved through base-catalyzed hydrolysis of the ester bonds is successfully shown to yield cannabidiol monomer after filtration, thereby paving the path towards full circularity of poly(cannabinoid)s.</p>

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Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems can be employed that interpret the natural electric signals produced by the human body as command inputs. One of these novel sensor systems is the myoelectric detection circuit, which can measure electromyographic (EMG) signals produced by contracting muscles through specialized electrodes, and convert the signals into a usable form through an analog circuit. With the goal of making a general-purpose myoelectric detection circuit platform for computer interface applications, several electrical circuit designs were iterated using OrCAD software, manufactured using PCB fabrication techniques, and tested with electrical measurement equipment and in a computer simulation. The analog circuit design culminated in a 1.35” x 0.8” manufactured analog myoelectric detection circuit unit that successfully converts a measured EMG input signal from surface skin electrodes to a clean and usable 0-5 V DC output that seamlessly interfaces with an Arduino Leonardo microcontroller for further signal processing and logic operations. Multiple input channels were combined with a microcontroller to create an EMG interface device that was used to interface with a PC, where simulated mouse cursor movement was controlled through the voluntary EMG signals provided by a user. Functional testing of the interface device was performed, which showed a long battery life of 44.6 hours, and effectiveness in using a PC to type with an on-screen keyboard.

<p> </p><div> <div> <div> <p> </p><div> <div> <div> <p> </p><div> <div> <div> <p>The current state of the art in biopotential recordings rely on radiative electromagnetic (EM) fields. In such transmissions, only a small fraction of this energy is received since the EM fields are widely radiated resulting in lossy inefficient systems. Using the body as a communication medium (similar to a ’wire’) allows for the containment of the energy within the body, yielding order(s) of magnitude lower energy than radiative EM communication. The first part of this work introduces Animal Body Communication for untethered rodent biopotential recording and for the first time this work develops the theory and models for animal body communication circuitry and channel loss. In vivo experimental analysis proves that ABC successfully transmits acquired electrocardiogram (EKG) signals through the body with correlation greater than 99% when compared to traditional wireless communication modalities, with a 50x reduction in power consumption. The second part of this work focusses on the analysis and design of an Electro-Quasistatic Human Body Communication (EQS-HBC) system for simultaneous sensing and transmission of biopotential signals. In this work, detailed analysis on the system level interaction between the sensing and transmitting circuitry is studied and a design to enable simultaneous sensing and transmission is proposed. Experimental analysis was performed to understand the interaction between the Right Leg-Drive circuitry and the HBC transmission along with the effect of the ADC quantization on signal quality. Finally, experimental trials proves that EKG signals can be transmitted through the body with greater than 96% correlation when compared to Bluetooth systems at extremely low powers. </p> </div> </div> </div> </div> </div> </div> </div> </div> </div>