Fabricating barbed microtip arrays by low-cost silicon wet etching techniques

This work presents the fabrication of barbed microtip arrays which utilizes the techniques of silicon wet etching. The KOH anisotropic wet etching was employed to form standard pyramidal microtip arrays, and HF/HNO3 isotropic etching was used to create barbs on those microtips. Experimental results show that the forces for detaching the barbed microtip arrays from a human skin, a PDMS polymer, and a PVC film are larger than the forces for the microtip arrays without barbs. The proposed barbed microtip arrays can be employed as the dry electroencephalogram (EEG) electrodes.