Stretchable and Soft Organic–Ionic Devices for Body‐Integrated Electronic Systems

Abstract

(3 of 23)www.advmattechnol.de Figure 2. Diagram of essential functions of a soft bionic sensory system, a body-integrated electronics system based on organic and ionic materials. Organic transistors on flexible and stretchable substrate: Organic transistors on flexible and stretchable substrate are operated with stability and reliability under mechanical deformation. Reproduced with permission. [146]

Nanoionics from Biological to Artificial Systems: An Alternative Beyond Nanoelectronics

“…The question now becomes “Is it possible to fabricate biological–artificial hybrid nanoionics‐based energy and information systems?” Human–machine interaction (HMI) is a typical biological–artificial information‐exchange system considering that most HMIs are based on electron transport. [ 132 , 133 ] However, nervous cells in biological systems communicate with each other by ions and chemical molecules (neurotransmitters), e.g., the generation and transmission of action potential. [ 134 ] Therefore, it is necessary to develop biological–artificial hybrid nanoionics that work on the principle of ion transport.…”

Robust Neural Interfaces with Photopatternable, Bioadhesive, and Highly Conductive Hydrogels for Stable Chronic Neuromodulation

“…Electroceuticals, based on the electrical stimulation of the peripheral nervous system, show great promise for therapeutic application in diverse diseases, such as hypertension, heart failure, gastrointestinal disorders, type II diabetes, and inflammatory disorders. − In recent NIH Stimulating Peripheral Activity to Relieve Conditions (SPARC) and DARPA Electrical Prescriptions (ElectRx) programs, which aim to develop bioelectronics medicine options for the treatment of inflammation, metabolism, and endocrine disorders, one of the exploratory technology goals is to innovate next-generation bioelectronics implants that can modulate electrical signals in peripheral nerves to control internal organ functions. , For neuromodulation of peripheral nerves with long-term stability and high efficiency, it is critical to construct a robust neural interface with intimate electrical coupling between neural electrodes and neural tissues. − In conventional bioelectronics approaches with peripheral nerves wrapped by the cuff electrodes, close contact between metal electrodes and the nerve trunk is achieved with a continuous compressive force which leads to the deformation of nerve and vascular tissues. − Moreover, substantial stress originating from the mechanical modulus mismatch between the stiff cuff and soft nerve can cause severe inflammatory reactions, accompanied by fibrous encapsulation which would block electrical communication at the neural interface and results in malfunctions of the implanted bioelectronics. Recently, efforts have been devoted to the development of new-generation implantable bioelectronics based on soft electronics with reduced mechanical mismatch and consequent adverse immune response for chronic implantation. − Despite a lot of progress in soft and compliant bioelectronics devices fabricated with ultrathin and flexible polymeric substrates, seamless integration of neural electrodes on the peripheral nerve is still a great challenge. − For example, a general strategy adopted to fix flexible neural electrodes on the peripheral nerves is to physically attach them to the epineurium surface. − However, such a weak physical interaction between neural electrodes and nerve tissues cannot ensure a tight contact at the bioelectronics-nerve interface for long-term stable electrical communication. Moreover, the widely used suturing method can cause adverse tissue damage and scar formation.…”

Recent Progresses in Liquid‐Free Soft Ionic Conductive Elastomers†

“…For instance, living matters mainly use ions as the charge carries to conduct electrical signals, so it is difficult for traditional electronic materials to mimic the biological sensory system. [ 69‐70 ] To tackle these limitations, soft conductive materials with ionic conducting properties are highly desirable.…”