Force controlled atomic force microscopy for biological specimen.

研究了聚酰亚胺悬臂梁用于力反馈方法的可行性。力反馈系统的稳定性主要是通过小的Q值和悬臂梁的低谐振频率来提高的。制作了聚酰亚胺悬臂梁，并对其机械性能，特别是真空中的Q值进行了研究。从这些值的力反馈系统所需的带宽估计。聚酰亚胺悬臂梁的频率要求降低到1/20，与具有相同功能的SiN悬臂梁相比，除了内部阻尼。通过数值仿真验证了系统的稳定性。带宽不足导致力曲线的大幅度振荡。为了提高Ti-6Al-4V的生物相容性，在O2 + H2O气氛中，采用ArF准分子激光器在抛光后的Ti-6Al-4V基体（0.1 ~ 3.0μmR）上沉积了羟基磷灰石（HAp）薄膜<max>，沉积过程中气压保持在13.3Pa（1×10 ~<-1>（-4）Torr）。衬底温度在500℃ ~ 5 ...更多信息 60℃。用X射线衍射（XRD）分析了HAp薄膜的晶体结构。当温度低于500℃时，薄膜为非晶态。当温度高于560℃时，薄膜为结晶HAp和磷酸三钙（TCP）的混合相。用原子力显微镜（AFM）观察了HAp薄膜的表面形貌。通过划痕试验和拉伸试验机的剥离试验来测量膜的机械性能。获得了以下结果：（1）在530℃左右得到结晶的HAp;（2）在划痕试验中，HAp膜在18 N的载荷下被明显去除;（3）在剥离试验中，HAp膜在表面粗糙度为0.1、1.0和3.0μmRmax的基底上的附着强度分别为2.3、5.4和10 MPa，（4）体外生物相容性评价。然而，力控原子力显微镜系统的稳定性不足以用于生物样品的研究。需要进一步改进力控制系统。少

Feasibility of polyimide cantilever for force feedback method is studied. The stability of the force feedback system is mainly improved by small Q factor and the low resonant frequency of the cantilever. The polyimide cantilever is fabricated and investigated its mechanical feature, especially Q factor in a vacuum. Form these values the required bandwidth of the force feedback system is estimated. The polyimide cantilever reduces the frequency requirement to 1/20, compared with the SiN cantilever with same feature except for internal damping. The system stability is confirmed by numerical simulations. The bandwidth shortage results in large oscillation of the force curve. To increase biological compatibility of Ti-6Al-4V, thin film of hydroxyapatite (HAp) was deposited on the polished substrate(0.1〜3.0μmR_<max>) by ArF excimer laser in an atmosphere of O_2+H_2O.The gas pressure was kept at 13.3Pa (1×10^<-1>Torr) during the deposition. The substrate temperature was varied torn 500℃ to 5 … More 60℃. Crystal stractures of HAp film were evaluated by X-ray diffraction (XRD). At temperatures less than 500℃ the films resulted in amorphous. At temperatures greater than 560℃ the films had mixture phase of crystallized HAp and tricalcium phosphate (TCP). Surface morphology of HAp film was observed by atomic-force microscope (AFM). Mechanical properties of film were measured by the scratch test and the peeling off test by using tensile test machine. The following results were obtained : (1) The crystallized HAp was obtained at about 530℃, (2) In the scratch test, HAp film was clearly removed at the load of 18N, (3) In the peeling off test, the adhesive strength of HAp film on the substratewere about 2.3, 5.4 and 10MPa for the surface roughness 0.1, 1.0 and 3.0μmRmax, respectively and (4) Biocompatibility of HAp film was evaluated by in-vitro. Unfortunately, to investigate biological specimen the stability of the force control atomic force microscopy system is not sufficient. Farther improvement of the force control system is required. Less