Bioresorbable silicon electronic sensors for the brain

Abstract

Many procedures in modern clinical medicine rely on the use of electronic implants in treating conditions that range from acute coronary events to traumatic injury. However, standard permanent electronic hardware acts as a nidus for infection: bacteria form biofilms along percutaneous wires, or seed haematogenously, with the potential to migrate within the body and to provoke immune-mediated pathological tissue reactions. The associated surgical retrieval procedures, meanwhile, subject patients to the distress associated with re-operation and expose them to additional complications. Here, we report materials, device architectures, integration strategies, and in vivo demonstrations in rats of implantable, multifunctional silicon sensors for the brain, for which all of the constituent materials naturally resorb via hydrolysis and/or metabolic action, eliminating the need for extraction. Continuous monitoring of intracranial pressure and temperature illustrates functionality essential to the treatment of traumatic brain injury; the measurement performance of our resorbable devices compares favourably with that of non-resorbable clinical standards. In our experiments, insulated percutaneous wires connect to an externally mounted, miniaturized wireless potentiostat for data transmission. In a separate set-up, we connect a sensor to an implanted (but only partially resorbable) data-communication system, proving the principle that there is no need for any percutaneous wiring. The devices can be adapted to sense fluid flow, motion, pH or thermal characteristics, in formats that are compatible with the body's abdomen and extremities, as well as the deep brain, suggesting that the sensors might meet many needs in clinical medicine.

Biomaterials for Enhancing Neuronal Repair

“…Flexible, transient, silicon-based, biocompatible, implantable biosensors are being developed that allow for wireless monitoring capability. They have been used successfully on skin, cardiac tissue, muscle, and the brain (Viventi et al, 2010(Viventi et al, , 2011Hwang et al, 2012;Kang et al, 2016). A wireless communication device composed of bioresorbable materials has been successfully implanted and used in rats for monitoring intracranial pressure and temperature (Kang et al, 2016).…”

“…New techniques and advances in material design, such as pore-enhanced hydrogels to promote neuronal alignment (Lee et al, 2015b), are facilitating targeted neuronal growth and repair. Innovations in neural monitoring through flexible, biodegradable electronics provide a means to understand these processes at a more fundamental level, as well as track and monitor repair in vivo (Viventi et al, 2011;Kang et al, 2016). These engineered interfaces address specific challenges inherent to damaged neural tissue by reducing glial scarring and overcoming limited distances of regeneration (Orive et al, 2009;Tam et al, 2014).…”

Recent Trends, Applications, and Challenges of Brain-Computer Interfacing (BCI)

“…These chips are inserted to measure the damaged areas of brain, usually after stroke, by measuring the temperature and pressure inside. After a particular time period these chips dissolve automatically causing no harm to the patient [22].…”

Designing the Health-related Internet of Things: Ethical Principles and Guidelines

“…Embedded environmental sensors can unobtrusively provide information about a patient's private space, including "smart home" systems for "ageing at home" or gerontechnologies to support frail patients (e.g., Marubeni's HRS-I, smart pillboxes and furniture, and fall detectors). Implantable, dissolvable wireless sensors can be ingested, injected or attached to the skin to measure pressure, temperature, pH, motion, flow and detect specific biomolecules [119]. Examples include in vivo glucose monitoring chips [120] and implantable stents for blood quality monitoring [78,121].…”