Microcantilever actuation via periodic internal heating

Abstract

This paper reports electrothermal actuation of silicon microcantilevers having integrated resistive heaters. Periodic electrical excitation induced periodic resistive heating in the cantilever, while the cantilever deflection was monitored with a photodetector. Excitation was either at the cantilever resonant frequency, f(0), f(0)/2, or f(0)/3. When the time averaged maximum cantilever temperature was 174 degrees C, the cantilever out-of-plane actuation amplitude was 484 nm near the cantilever resonance frequency of 24.9 kHz. This actuation was sufficiently large to operate the cantilever in intermittent contact mode and scan a calibration grating of height of 20 nm.

2-ω and 3-ω temperature measurement of a heated microcantilever

“…The cantilever can have large thermomechanical oscillations if periodically heated at its resonant frequency. 10 However, the cantilever strain has a negligible effect on cantilever …”

“…The nature of the correction of Eq. (10) requires that it should be done first, before the other corrections.…”

“…9 Periodic thermomechanical actuation also allows nanometer-scale topography imaging. 10 Several published articles report the investigation of heat generation and heat flow within heated AFM cantilevers, [11][12][13][14] which has led to a clear understanding of the temperature within and near the heated cantilever. 1,2,[15][16][17][18] However, most articles show cantilever temperature calibration during steady-state heating 2,4,15,19 or pulsed heating.…”

“…11,[20][21][22] A few articles have investigated the thermal behavior of heated AFM cantilevers during periodic heating. 10,23 While these articles describe the linear and nonlinear frequency-domain behaviors of a heated AFM cantilever, they do not provide a clear methodology for measuring periodic cantilever temperature.…”

Scanning thermal lithography for nanopatterning of polymers

“…Besides SThL, the use of heated AFM probes has been reported among others for (nanoscale) thermal analysis (NanoTA), 10,122,[136][137][138] thermal cantilever actuation, [139][140][141] on cantilever processes, 142,143 SThM 9, 144,145 and topography imaging. 77,146,147 These applications were nicely reviewed by Nelson and King 87 and are therefore not further described here.…”