A PDMS dermal patch for non-intrusive transdermal glucose sensing

Abstract This paper describes the fabrication of an adhesive bandage comprised of multiple, compliant polydimethylsiloxane (PDMS) micro-fluidic elements to perform controlled and non-intrusive transdermal sampling of glucose, or any other bio-molecule present in interstitial fluids. The patch-like device, to be worn on the skin, has PDMS component layers that form vertically oriented micro-fluidic channels and reservoirs. In addition, micro-heater elements are integrated onto the PDMS layer that will be in contact with the skin, and are used to thermally ablate tiny micro-pores through only the dead-skin layer, allowing for easier diffusion of normally trapped bio-molecules, such as glucose, to the skin surface. The dermal patch, containing micro-channels and fluid-encapsulated reservoirs, assist in the transport of glucose molecules from just beneath the dead-skin layer to a colorimetric detection membrane situated on top of the bi-layer PDMS patch. This paper will focus on the fabrication of the prototype PDMS patch and the challenges encountered during wafer-scale batch production. Preliminary in vitro studies using human graft skin samples are included to illustrate the non-inflammatory micro-ablation procedure.