Bioresorbable Multilayer Photonic Cavities as Temporary Implants for Tether-Free Measurements of Regional Tissue Temperatures

Design and Development of Transient Sensing Devices for Healthcare Applications

With the ever-growing requirements in the healthcare sector aimed at personalized diagnostics and treatment, continuous and real-time monitoring of relevant parameters is gaining significant traction. In many applications, health status monitoring may be carried out by dedicated wearable or implantable sensing devices only within a defined period and followed by sensor removal without additional risks for the patient. At the same time, disposal of the increasing number of conventional portable electronic devices with short life cycles raises serious environmental concerns due to the dangerous accumulation of electronic and chemical waste. An attractive solution to address these complex and contradictory demands is offered by biodegradable sensing devices. Such devices may be able to perform required tests within a programmed period and then disappear by safe resorption in the body or harmless degradation in the environment. This work critically assesses the design and development concepts related to biodegradable and bioresorbable sensors for healthcare applications. Different aspects are comprehensively addressed, from fundamental material properties and sensing principles to application-tailored designs, fabrication techniques, and device implementations. The emerging approaches spanning the last 5 years are emphasized and a broad insight into the most important challenges and future perspectives of biodegradable sensors in healthcare are provided.

Materials and Device Designs for Wireless Monitoring of Temperature and Thermal Transport Properties of Wound Beds during Healing

Chronic wounds represent a major health risk for diabetic patients. Regeneration of such wounds requires regular medical treatments over periods that can extend for several months or more. Schemes for monitoring the healing process can provide important feedback to the patient and caregiver. Although qualitative indicators such as malodor or fever can provide some indirect information, quantitative measurements of the wound bed have the potential to yield important insights. The work presented here introduces materials and engineering designs for a wireless system that captures spatio-temporal temperature and thermal transport information across the wound continuously throughout the healing process. Systematic experimental and computational studies establish the materials aspects and basic capabilities of this technology. In vivo studies reveal that both the temperature and the changes in this quantity offer information on wound status, with indications of initial exothermic reactions and mechanisms of scar tissue formation. Bioresorbable materials serve as the foundations for versions of this device that create possibilities for monitoring on and within the wound site, in a way that bypasses the risks of physical removal.

Advances in Bioresorbable Materials and Electronics

Transient electronic systems represent an emerging class of technology that is defined by an ability to fully or partially dissolve, disintegrate, or otherwise disappear at controlled rates or triggered times through engineered chemical or physical processes after a required period of operation. This review highlights recent advances in materials chemistry that serve as the foundations for a subclass of transient electronics, bioresorbable electronics, that is characterized by an ability to resorb (or, equivalently, to absorb) in a biological environment. The primary use cases are in systems designed to insert into the human body, to provide sensing and/or therapeutic functions for timeframes aligned with natural biological processes. Mechanisms of bioresorption then harmlessly eliminate the devices, and their associated load on and risk to the patient, without the need of secondary removal surgeries. The core content focuses on the chemistry of the enabling electronic materials, spanning organic and inorganic compounds to hybrids and composites, along with their mechanisms of chemical reaction in biological environments. Following discussions highlight the use of these materials in bioresorbable electronic components, sensors, power supplies, and in integrated diagnostic and therapeutic systems formed using specialized methods for fabrication and assembly. A concluding section summarizes opportunities for future research.

Multifunctional Biosensing Platform Based on Nickel-Modified Laser-Induced Graphene

Nickel plating electrolytes prepared by using a simple salt solution can achieve nickel plating on laser-induced graphene (LIG) electrodes, which greatly enhances the electrical conductivity, electrochemical properties, wear resistance, and corrosion resistance of LIG. This makes the LIG-Ni electrodes well suited for electrophysiological, strain, and electrochemical sensing applications. The investigation of the mechanical properties of the LIG-Ni sensor and the monitoring of pulse, respiration, and swallowing confirmed that the sensor can sense insignificant deformations to relatively large conformal strains of skin. Modulation of the nickel-plating process of LIG-Ni, followed by chemical modification, may allow for the introduction of glucose redox catalyst Ni2Fe(CN)6 with interestingly strong catalytic effects, which gives LIG-Ni impressive glucose-sensing properties. Additionally, the chemical modification of LIG-Ni for pH and Na+ monitoring also confirmed its strong electrochemical monitoring potential, which demonstrates application prospects in the development of multiple electrochemical sensors for sweat parameters. A more uniform LIG-Ni multi-physiological sensor preparation process provides a prerequisite for the construction of an integrated multi-physiological sensor system. The sensor was validated to have continuous monitoring performance, and its preparation process is expected to form a system for non-invasive physiological parameter signal monitoring, thus contributing to motion monitoring, disease prevention, and disease diagnosis.

Bioresorbable Photonics: Materials, Devices and Applications

Bio-photonic devices that utilize the interaction between light and biological substances have been emerging as an important tool for clinical diagnosis and/or therapy. At the same time, implanted biodegradable photonic devices can be disintegrated and resorbed after a predefined operational period, thus avoiding the risk and cost associated with the secondary surgical extraction. In this paper, the recent progress on biodegradable photonics is reviewed, with a focus on material strategies, device architectures and their biomedical applications. We begin with a brief introduction of biodegradable photonics, followed by the material strategies for constructing biodegradable photonic devices. Then, various types of biodegradable photonic devices with different functionalities are described. After that, several demonstration examples for applications in intracranial pressure monitoring, biochemical sensing and drug delivery are presented, revealing the great potential of biodegradable photonics in the monitoring of human health status and the treatment of human diseases. We then conclude with the summary of this field, as well as current challenges and possible future directions.