Advancing Atomic Force Microscopy Tips with 3D Design Control and Reduced Hamaker Constant

In this work, we deploy two-photon polymerization (2PP) technique for generating multipurpose polymer-based atomic force microscopy (AFM) tips, referred to as 3DTIPs, with great flexibility in design and function. With the rationale that 3DTIPs could complement or even substitute conventional silicon tips, we show that when compared, the 3DTIPs prove effective in obtaining high resolution, high speed AFM images in air and liquid using common AFM modes. In particular, we demonstrate that the 3DTIPs provide high resolution imaging due to their extremely low Hamaker constant, high speed scanning rates due to their low quality factor, and high durability due to their soft nature and minimal isotropic tip wear, the three important features for advancing the imaging with next generation AFM tips. We also show that, refining the tip end of the 3DTIPs by carbon nanotube inclusion substantially extends their functionality in high resolution AFM imaging, reaching angstrom scales. Altogether, multifunctional capabilities of 3DTIPs have potential to substitute conventional silicon tips for effectively performing various AFM applications.