Unlocking Thin-Film & Interface Insights with BioNavis QCMD

A concise technical overview

Introduction

The BioNavis QCMD system offers real-time, label-free measurement of thin film and interface behaviour by simultaneously monitoring resonant frequency shifts (Δf) and dissipation changes (ΔD) of a quartz sensor. By combining mass loading (via Δf) with viscoelastic/mechanical information (via ΔD), the technique is highly relevant for precise surface/coating layer characterization. BioNavis+1

Below we review published BioNavis QCMD application notes and research-oriented case-studies, showing how this platform has been used for thin films, bilayers, multilayers, and electrochemical film systems.

Key Published Applications

Supported Lipid Bilayer (SLB) Formation

• In Application Note #10 (“Supported lipid bilayer formation on a solid substrate monitored by QCMD”) the BioNavis QCMD instrument was used to monitor the real-time formation of a lipid bilayer from adsorbed liposomes on a SiO₂-coated sensor. BioNavis+1
• The data showed a characteristic signature: an initial large drop in Δf (mass loading of liposomes) and rise in ΔD (soft/vesicular layer), followed by stabilisation at an asymptotic Δf (~ –26.4 Hz) and ΔD ~ 0.2×10⁻⁶ after bilayer formation. BioNavis
• This demonstrates the platform’s ability to closely monitor film formation kinetics and viscoelastic transitions from vesicle to bilayer.
  Take-away: QCMD via BioNavis enables quantification of thin film formation + mechanical stability in real time.

Polyelectrolyte Multilayer (Layer-by-Layer) Deposition

• In Application Note #11 (“Polyelectrolyte Layer-by-Layer Assembly Using QCMD”) the BioNavis QCMD 110 instrument tracked deposition cycles of PEI/PSS/PAH on a sensor at 7 overtones, recording both Δf and ΔD for each deposition and rinse step. BioNavis
• The note discusses interpretation using both the simple Sauerbrey model (rigid film) and a viscoelastic (Voigt) model for hydrated/soft films, emphasising that ΔD provides key information on hydration and mechanical compliance. BioNavis
  Take-away: The system can handle multilayer thin films with varying viscoelastic behaviour—a frequent scenario in advanced coatings.

Electrochemical Thin-Film / Electrode Monitoring

• In Application Note #12 (“Li-ion intercalation in composite LiFePO₄ electrodes monitored by QCMD”) the BioNavis QCMD platform tracked gravimetric changes during charge/discharge of an LFP electrode coated onto the quartz sensor. The results confirmed structural stability (negligible ΔD change) and purely gravimetric mass loading behaviour. BioNavis
• This demonstrates the BioNavis QCMD’s compatibility with electrochemical set-ups, enabling simultaneous measurement of electrode processes in situ. BioNavis+1
  Take-away: The platform supports complex film behaviour under electrochemical stress, including thin-film electrode coatings.

Summary of Technical Capabilities & Benefits

• Mass + mechanical insight: By tracking both Δf and ΔD, the BioNavis QCMD delivers information on mass loading and the rigidity/viscoelasticity of the film. BioNavis
• High sensitivity & multi-overtone capability: The instrument supports multiple overtones (e.g., fundamental +6) enabling depth/film-modulus sensitivity. BioNavis+1
• Real-time monitoring: The instrument allows continuous tracking of dynamic processes (adsorption, film formation, electrochemical cycling).

Versatility: Applicable in liquid and gas media, compatible with coatings, biomembranes, electrode films, multilayers.