Abstract Electronic visual prostheses, or biomimetic eyes, have shown the feasibility of restoring functional vision in the blind through electrical pulses to initiate neural responses artificially. However, existing visual prostheses predominantly use wired connections or electromagnetic waves for powering and data telemetry, which raises safety concerns or couples inefficiently to miniaturized implant units. Here, we present a flexible ultrasound-induced retinal stimulating piezo-array that can offer an alternative wireless artificial retinal prosthesis approach for evoking visual percepts in blind individuals. The device integrates a two-dimensional piezo-array with 32-pixel stimulating electrodes in a flexible printed circuit board. Each piezo-element can be ultrasonically and individually activated, thus, spatially reconfigurable electronic patterns can be dynamically applied via programmable ultrasound beamlines. As a proof of concept, we demonstrate the ultrasound-induced pattern reconstruction in ex vivo murine retinal tissue, showing the potential of this approach to restore functional, life-enhancing vision in people living with blindness. 

/pdf/flexible-ultrasound-induced-retinal-stimulating-piezo-arrays-14n8cc8l.pdf

Flexible ultrasound-induced retinal stimulating piezo-arrays for biomimetic visual prostheses

Ultrasound-driven in vivo electrical stimulation based on biodegradable piezoelectric nanogenerators for enhancing and monitoring the nerve tissue repair

Electrospun Fiber-Based Flexible Electronics: Fiber Fabrication, Device Platform, Functionality Integration and Applications

Miniature wireless bioelectronic implants that can operate for extended periods of time can transform how we treat disorders by acting rapidly on precise nerves and organs in a way that drugs cannot. To reach this goal, materials and methods are needed to wirelessly transfer energy through the body or harvest energy from the body itself. We review some of the capabilities of emerging energy transfer methods to identify the performance envelope for existing technology and discover where opportunities lie to improve how much—and how efficiently—we can deliver energy to the tiny bioelectronic implants that can support emerging medical technologies. Description Editor’s summary Bioelectronic devices that can sense or manipulate biological signals, such as pacemakers that can detect and regulate irregular cardiac cycles, can dramatically improve the health and lifestyle of the patients who use them. However, these devices are often limited by the storage capacity of an onboard battery or are tethered to wires that can cause infection. Nair et al. reviewed advances in developing alternate methods to generate, transmit, and store electrical charge that enable wireless power transfer and energy harvesting safely through and within the human body. In addition to removing power limitations, these advances often also enable communication from a device or possibly even between devices. —Marc S. Lavine A review describes methods to enable wireless power transfer and energy harvesting through and within the human body. BACKGROUND Bioelectronics, electronic devices that sense or manipulate biological signals, can substantially improve medical outcomes by modulating the activity of excitable cells and tissues in the nervous system, cardiovascular system, and beyond. This specific stimulation and monitoring can reduce side effects and adapt in real time to the needs of each patient. However, despite the potential for bioelectronics to treat numerous conditions, only few implanted bioelectronic devices are currently the standard of care. These include cardiac pacemakers that use electrical impulses to synchronize the contraction of heart cells and continuous glucose monitors that generate an electronic alert when a user needs insulin. Large battery packs, cumbersome tethers, and intricate packaging architectures complicate device design and present numerous possible failure modes, which limits the widespread deployment of therapeutic implantable bioelectronic devices. Wires can break and provide a pathway for infection. Furthermore, the need to route wires and leads limits the number and location of bioelectronic sensing and stimulating sites. Battery packs also create challenges for wearable bioelectronics such as heart rate monitors or pulse oximeters because the added size and weight of batteries limit the overall comfort, appearance, and ease of use. Bioelectronic devices that operate without batteries could be miniaturized to millimeter-scale dimensions and easily implanted or comfortably worn. This approach would allow distributed networks of sensors and actuators to measure and manipulate physiological activity throughout the body to enable precise and adaptive bioelectronic therapies with minimal risks or interference with daily activities. To reach this level of miniaturization, bioelectronics must receive power from an external transmitter or harvest energy from the body itself. Unfortunately, traditional methods of transmitting wireless power over long distances rely on electromagnetic waves that are absorbed or reflected by the body. To overcome this challenge, recent innovations in wireless power transfer and energy-harvesting technologies have been leveraged to support the power requirements of bioelectronic devices. These include ultrasound, electromagnetic, magnetic, and optical methods to deliver power and data safely through the body, as well as energy-harvesting methods that extract chemical, kinetic, and thermal energy from the body itself. These emerging materials and technologies for data and power transfer are allowing bioelectronic devices to be miniaturized with tiny rechargeable batteries or, in the extreme case, made entirely battery free. ADVANCES We review progress in the materials and methods that are enabling wireless power transfer and energy harvesting safely through and within the human body. These methods must contend with the fact that many forms of energy are absorbed or reflected by bone and soft tissues, placing limits on the safety and efficiency of traditional power and data transmission technologies. To overcome these challenges, piezoelectric, photovoltaic, and magnetoelectric materials are being evaluated for use in nontraditional energy transfer techniques because they have unique advantages in the context of power transfer through the human body. Similarly, materials such as triboelectrics, magnetoelastics, and thermoelectrics are being explored to harvest energy from the human body. Furthermore, the emerging methods for power transfer through the human body are also being explored as a means for efficient data communication channels that will support wireless networks or miniature implantable bioelectronics. OUTLOOK The extreme miniaturization and long functional lifetime that are enabled by battery-free technologies point toward a future in which networks of tiny bioelectronics could be distributed throughout the body to accurately sense physiological states and apply therapies when and where they are needed. Reaching this vision will require additional scientific advances in manufacturing and packaging of the materials that support this wireless bioelectronic network. For example, to reach submillimeter scale, alternatives to traditional hermetic seals must be explored to protect these electronics from the harsh environment of the human body. In addition to typical material biocompatibility, implantable bioelectronics will have a longer operating lifespan if there is little to no foreign body tissue response and scar formation to degrade the recording or stimulation efficacy. Advances in nanomaterials, soft electronics, and coatings with growth factors, anti-inflammatory drugs, and peptides are underway, but ultimately these technologies need more in vivo testing throughout different regions of the body. This is especially critical if we are to propel bioelectronic devices into true distributed networks inside and nearby different organs and tissues throughout the body, each with their own movements, vasculature, immune cells, and repair mechanisms. Furthermore, distributed implanted bioelectronics will require specialized data and power transfer modalities that will need systems and standards for these emerging communication and energy transfer methods. For continued long-term success, power and data transfer modalities must be efficient, safe, secure, reliable, and able to be updated as new implants and methods arise. Battery-free bioelectronics. Miniature bioelectronics could support myriad therapeutics.

Miniature battery-free bioelectronics

Integrated internal ion-gated organic electrochemical transistors for stand-alone conformable bioelectronics.

Abstract Implantable bioelectronic devices for the simulation of peripheral nerves could be used to treat disorders that are resistant to traditional pharmacological therapies. However, for many nerve targets, this requires invasive surgeries and the implantation of bulky devices (about a few centimetres in at least one dimension). Here we report the design and in vivo proof-of-concept testing of an endovascular wireless and battery-free millimetric implant for the stimulation of specific peripheral nerves that are difficult to reach via traditional surgeries. The device can be delivered through a percutaneous catheter and leverages magnetoelectric materials to receive data and power through tissue via a digitally programmable 1 mm × 0.8 mm system-on-a-chip. Implantation of the device directly on top of the sciatic nerve in rats and near a femoral artery in pigs (with a stimulation lead introduced into a blood vessel through a catheter) allowed for wireless stimulation of the animals’ sciatic and femoral nerves. Minimally invasive magnetoelectric implants may allow for the stimulation of nerves without the need for open surgery or the implantation of battery-powered pulse generators. 

/pdf/a-wireless-millimetric-magnetoelectric-implant-for-the-1rkoea9j.pdf

A wireless millimetric magnetoelectric implant for the endovascular stimulation of peripheral nerves

Minimally invasive neural interfaces can be used to diagnose, manage, and treat many disorders with substantially reduced risks of surgical complications. Endovascular neural interfaces implanted in the veins or arteries is one approach, but it requires prescriptions of anti-thrombotic medication and are likely not explantable after endothelialization. More critically, the approach is limited by the small size and location of blood vessels, such that many important cortical, subcortical, spinal targets cannot be reached. Here, we demonstrate a chronic endocisternal neural interface that approaches brain and spinal cord targets through inner and outer cerebral spinal fluid (CSF) spaces. These spaces surround the nervous system and lack the tortuosity of the circulatory system, giving us access to the entire brain convexity, deep brain structures within the ventricles, and the spinal cord from the spinal subarachnoid space. Combined with miniature magnetoelectric-powered bioelectronics, the entire wireless system is deployable through a percutaneous procedure. The flexible catheter electrodes can be freely navigated throughout the body from the spinal to cranial subarachnoid space, and from the cranial subarachnoid space to the ventricles. We show in a large animal model that we can also reposition the recording and stimulation electrodes or explant the neural interface after chronic implantation. This enables applications in therapies that require transient or permanent brain/machine interface such as stroke rehabilitation and epilepsy monitoring and opens a new class of minimally invasive endocisternal bioelectronics.

Endocisternal interfaces for minimally invasive neural stimulation and recording of the brain and spinal cord

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Scott Crosby

Author Tools

Chat about Author

Papers

A wireless millimetric magnetoelectric implant for the endovascular stimulation of peripheral nerves

Endocisternal interfaces for minimally invasive neural stimulation and recording of the brain and spinal cord