Compensation of stray capacitance of the quartz tuning fork for a quantitative force spectroscopy

• Stray capacitance of the QTF sensor was compensatated using a tied-prong QTF.
• Principle of compensation process was explained with resonance curves of the QTF.
• The quantitative force measurements fit in well with the theoretical compensation.
• The quality factor can be achieved from ∼10 to ∼30,000.
• The viscoelasticity of the confined nano-water was studied by the proposed device.

We have introduced a simple but robust approach to realize stray-capacitance compensation of a quartz tuning fork force gradient sensor by using a tied-prong of the same tuning fork instead of using a variable precision capacitor. The results of quantitative force measurements with the proposed device show excellent agreement with the numerical method of cancellation via the theoretical compensation method with the resonance response curves. Futhermore, the mechanical properties of the condensed nano-water bridges are investigated with the proposed compensator, which provides the potential promise of the intrinsic quartz tuning fork for a quantitative precision force spectroscopy.