This paper presents a miniaturized transparent electrochemical dopamine sensor system which is capable of dopamine detection and provides in vitro optical imaging. The dopamine sensor based on the 3-electrode system was miniaturized into a single device using the micro-electromechanical system. The transparent working electrode was successfully fabricated using nanosphere lithography. The working electrode was functionalized with overoxidized polypyrrole/sodium dodecyl sulfate-modified carbon nanotube (OPPy/SDS-CNT) and was found to be highly sensitive and selective in detecting dopamine. Owing to its small size, transparency, and simple fabrication process, the purposed platform shows a potential for a next-generational multi-modal in vitro analysis system.
To decrease the limit of detection of imaging of extracellular ATP dynamics in the brain, we developed a redox-type, highly sensitive, label-free ATP image sensor with a reasonable spatial resolution ($37.3\ \ \mu\mathrm{m}$-pitch) effective utilization in in-vitro experiments. The lowest detectable concentration achieved in our sensor, which is based on hydrogen peroxide detection techniques using redox enzymes, was $3\ \mu \mathrm{M}$. Further, according to the results of the in-vitro biological experiment conducted using a 10 mM-HEPES buffer, our sensor demonstrated a 100 times superior performance compared to the existing imaging devices that were also based on hydrogen ion (H+) detection techniques. It is expected that our novel ATP image sensor can be successfully applied for highly sensitive imaging of ATP released from brain nerve tissues and cells. It also has potential application in the spatiotemporal analysis of ATP.
The development of a multimodal sensing platform with multiple layers for electronic skin (e-skin) sensing of temperature and pressure has attracted considerable interest to practical applications in soft robotics, human-machine interfaces, and wearable health monitoring. In this work, we demonstrated a new platform technology with multiple sandwiched layers of highly oriented carbon nanotube membrane and polyacrylonitrile for the integration of pressure and temperature sensory functionalities into a single platform that is thin, ultra-lightweight, flexible, and wearable. The key technology of in situ deposition of sensor platform on objects or in robot interface makes this a unique method for the development of e-skins for robotic applications, offering a new approach to wearable electronics and portable health care.
This work reports on the first ultra-low power infrared (IR) wireless sensor based on an IR micromechanical photoswitch (MP) and a microcontroller capable of quantifying the above-threshold input IR radiation and transmitting the measured value wirelessly. The entire sensor node remains asleep (standby power ∼811 nW) until awakened by the always-alert IR digitizer (i.e., the MP) upon exposure to targeted IR radiation. Unlike existing switch-based zero power sensors that only provide a binary output (i.e., indicate the presence of an IR source), the awakened sensor exploits a thermally-modulated electromechanical pull-in mechanism to measure the incident IR power using the same MP, the value of which is then transmitted wirelessly to a remote gateway. The prototype demonstrated here paves the way for maintenance-free coin battery-powered sensors for longterm and high-granularity remote deployment.
Electric field sensors are widely used in many fields. MEMS based electric field sensor has the advantages of small size, light weight and low power consumption. It can not only be used to upgrade the traditional electric field detection equipment, but also meet the needs for a lot of new applications. This presentation will review briefly the research and development of MEMS based electric field sensors, report the work and progress of the author's team, provide examples of practical applications, prospect for the future work and potential new applications, and discuss about the difficulties and problems.
