Rapid, low cost prototyping of transdermal devices for personal healthcare monitoring

Abstract

The next generation of devices for personal healthcare monitoring will comprise molecular sensors to monitor analytes of interest in the skin compartment. Transdermal devices based on microneedles offer an excellent opportunity to explore the dynamics of molecular markers in the interstitial fluid, however good acceptability of these next generation devices will require several technical problems associated with current commercially available wearable sensors to be overcome. These particularly include reliability, comfort and cost. An essential pre-requisite for transdermal molecular sensing devices is that they can be fabricated using scalable technologies which are cost effective.We present here a minimally invasive microneedle array as a continuous monitoring platform technology. Method for scalable fabrication of these structures is presented. The microneedle arrays were characterised mechanically and were shown to penetrate human skin under moderate thumb pressure. They were then functionalised and evaluated as glucose, lactate and theophylline biosensors. The results suggest that this technology can be employed in the measurement of metabolites, therapeutic drugs and biomarkers and could have an important role to play in the management of chronic diseases.

Dermal Microdialysis in Pharmacokinetics

“…The mean age of participants was 42 years (SD 14) and seven (70%) of ten participants were men. Participants mean height was 174 cm (11), weight 74 kg (15), and BMI 24 kg/m² (3). Mean creatinine clearance was 114 mL/min (29).…”

Disposable Sensors in Diagnostics, Food, and Environmental Monitoring

“…Measurements made using the interstitial fluid, however, offer an alternative, more accurate route to measuring blood glucose indirectly. The interstitial fluid can be accessed either noninvasively using a tattoo‐like device or minimally invasively using an array of functionalized microneedles in the form of a patch (that penetrate the dermis) . Another interesting approach is the simultaneous monitoring of sweat and interstitial fluid using a disposable wearable biosensor .…”

Review—The Development of Wearable Polymer-Based Sensors: Perspectives

“…To fabricate a microneedle array on a conductive elastomer, photo-lithography, 114 injection moulding, 71 soft lithography (e.g., replica moulding 115 and embossing 116,117 ), and 3D printing 118 are commonly used. In photo-lithography, the material surface is covered with photo-resist materials and is irradiated with masked ultraviolet followed by etching of the photoresist material developing desirable pattern on the surface.…”