Article by Eloy Sanchez & Roberta Lock
From Cells to Cell Phones:
A Wearable Microneedle Sensor
An integrated wearable microneedle array for the continuous monitoring of multiple biomarkers in interstitial fluid, Nature Biomedical Engineering, 2022
Farshad Tehrani et al., Joseph Wang Lab
Health monitoring devices include a wide array of technologies that provide patients and health care workers with vital information that can warn of life-threatening illness early. In an ideal device, extensive amounts of internal body system data should be obtainable with minimal patient discomfort and maximum ease of access. Unfortunately, this ideal still does not exist as most inclusive analysis can only be conducted with invasive techniques performed within a clinic, and non-invasive methods of data collection aren’t comprehensive. In this paper, researchers have developed a non-invasive method of monitoring two simple biomarkers present within the interstitial fluid via a wearable, skin adhering device that connects to a smartphone!
What did these researchers do?
To give the user important information about their body, a sensor, electronics, software, and a smartphone app work together. Researchers tested this device by having users perform different activities; eating, drinking, and exercising, and then comparing their novel device’s readings with the readings from more established, standardized measurement techniques.
Microneedle sensor patch by J. Wang Lab
Why is this important?
Monitoring certain cellular substances is important in the maintenance or detection of certain diseases. By having a device that adheres to the skin for continuous access to the interstitial fluid that provides this important biological data, the number of finger-pricks and standard blood withdrawal needles traditionally necessary no longer need to occur as frequently. Additionally, connecting this device to an app on a smartphone increases the ease of access to personalized healthcare.
How did the researchers do this?
The monitoring device’s design consists of two sections-- a disposable adhesive piece attached to a reusable electronics component. Each aspect of the device was then tested for performance. Does the device stick to the skin properly and does it remain sterile so as not to cause infection? How much pressure the adhesive needed, and the sterility of the setup were both tested. Can the device on the skin transmit information wirelessly to a phone, and is it chargeable? A small circuit board was created that would act as the electronics section and the wireless charging capabilities were tested. Finally, the full device was tested by monitoring users undergoing specific workouts and eating specific foods to see if it gave accurate recordings of the user’s biomarkers under a variety of different settings and over a period of time.
What comes next?
Although incredibly neat, this device can currently only record information about biomarkers that can otherwise be obtained by standard blood withdrawals or finger pricks. Additionally, the constant obtaining of measurements for the device does lead to the battery draining over time (~4 days of charge). Going forward, scientists hope to improve the battery life, incorporate calibration technologies, increase the sample size of participants used for testing, and increase the number of biomarkers that can be simultaneously analyzed by the device.