Development of a micromechanical thermogravimetric tool for investigation of biominerals

生物矿物因其独特的性质、层级结构和混合组成(有机-无机复合材料)而成为开发新材料的灵感来源。这种被捕获的材料在决定其本征性质方面起着重要的作用。因此，必须测量有机化合物的准确含量和分布，并进一步将其与给定的特定性质(如机械性能)相关联。然而，这些测量受到数量/大小的限制，即mm-cm和/或&gt；50 mg，并限于使用经典的热重分析。该项目旨在开发和实现一种热重分析方法，能够分析质量小至1 ng、质量分辨率为1pg的微小物体的有机含量。对微小尺寸的单独选择的对象的直接分析将允许我们消除与批量分析相关的人工制品。这种分析技术是基于共振加热的微结构(悬臂梁)，根据共振频率的变化，我们可以量化温度引起的质量变化(1PG)。在方法学建立后，合成的和天然的碳酸钙生物矿物都将被用作概念验证。有机质量含量与其分布(由扫描力显微镜确定)之间的相关性将被揭示。此外，我们的目标是开发以下目标：a)通过用生物分子功能化微器件的可加热尖端并促进CaCO3在微器件上的直接结晶来在线监测结晶过程(质量负载测定)。此外，还将进行有机含量本地测定；b)开发定制的高性能微型设备，具有高Q因数分辨率、均匀的温度分布和定义的样品平台，并与我们的合作伙伴(印度理工学院Rao教授)合作；c)对可加热的微型设备进行原位红外吸收测量，以便直接监测与有机影响无关的晶体相变(非晶态-结晶)(加拿大阿尔伯塔大学的Thundat教授)。

Biominerals are a source of inspiration for the development of new materials given their unique properties, hierarchical organization and hybrid composition (organic-inorganic composites). This trapped material plays an important role in determining its intrinsic properties. Thus, both the exact content and the distribution of organic compounds must be measured and further correlated to given specific property (e.g. mechanical). However, these measurements are limited by quantity/size constrains, i.e., mm-cm and/or >50 mg and to the use of classical thermogravimetric analysis. This project aims to develop and implement a thermogravimetric analysis capable of analyzing the organic content micro-sized objects with masses as small as 1 ng with mass resolution of 1pg. The direct analysis of microsized, individually selected objects will allow us to eliminate artifacts associated with bulk analysis. This analytic technique is based on a resonating heated microstructure (cantilever) that, upon resonance frequency shifts, will allow us to quantify temperature-induced mass changes (1pg). Upon methodology establishment, both synthetic and natural CaCO3-based biominerals will be used as proof-of-concept. A correlation between organic mass content and its distribution (determined by scanning force microscopy) will be revealed. Further, we aim to develop the following goals: a) in situ monitoring of crystallographic processes (mass loading determination) by functionalizing the microdevices heatable tips with biomolecules and promoting CaCO3 direct crystallization onto the microdevice. In addition local determination of organic content will be performed; b) development of a custom-made high performance microdevices with high Q-factors resolution, a uniform temperature distribution and a defined sample platform together with our cooperation partner (Prof. Rao, IIT, India); c) implementation of in situ IR-absorption measurements carried out on heatable microdevices for direct monitoring of crystal phase-transitions (amorphous-crystalline) not associated with an organic influence (Prof. Thundat, University Alberta, Canada).