Design Project-Graphene Resonator
GHz Graphene Nanomechanical Resonators
MECE E4212
12/12/2011
Xu Cui Tim Olsen Mark Stothers Sung Hoon (Steven) Yoon
Introduction
Resonators are used to either generate waves of specific frequencies or to select specific frequencies from a signal. At the same time, devices ranging from nanoscale resonators, switches, and valves have applications in tasks as diverse as information processing, molecular manipulation, and sensing. High quality resonating systems, providing high frequency resolution and long energy storage time, play an important role in many fields of physics. In particular in the field of nano-electromechanical systems (NEMs), recent research has led to the development of high frequency top-down fabricated mechanical resonators with high-quality factors.
The ultimate limit would be a resonator one atom thick, but this puts severe constraints on the material. It is doubtless that the enormous stiffness and low density of graphene make it an ideal material for NEMs applications. Though mechanical resonators are miniaturized to make them lighter and to increase their resonance frequency, the quality factor tends to decrease significantly from surface effects. High Q values combined with high resonance frequencies are an important prerequisite for applications such as single-atom mass sensing and fundamental studies of the quantum limit of mechanical motion.
Device Fabrication
Graphene flakes (Toshiba Ceramics) were deposited on a SiO2/Si substrate by mechanical exfoliation, optically located by their contrast and subsequently confirmed to be monolayers with Raman spectroscopy. Metal electrodes (chromium/gold) were patterned on the graphene by electron-beam lithography. An optional second step of lithography and oxygen plasma etching could be used to shape the graphene after patterning of electrodes. The devices were then suspended by etching the SiO2 epilayer using buffered oxide etchant, followed by critical point drying to suspend the graphene between the electrodes. This permits suspension of devices with a uniform gap below the graphene, even for sheets with dimensions over 1 μm. The resulting wide suspended graphene sheets are low-impedance devices, which is helpful in matching to high-frequency electronics. Lithographic control also allows narrow ribbon resonators. The combination of optical thickness identification and lithographic patterning gives us full three-dimensional knowledge of the device geometry. Although the oxide layer below the graphene in the area covered by the electrode is removed in the etching process, the adhesion between graphene and metal still provides good mechanical clamping.
Figure 1 (Left)SEM image of suspended graphene nanoribbon, lithographically patterned to a width of 200 nm before suspension. (Right) Schematic of suspended graphene. The SiO2 under the entire graphene flake is etched evenly, including the contact region.
Resonator Model Description
Some parameters of the graphene may vary from device to device. For example, post-processing of the wafer yields small residual layers of pentacene and PMMA which affect the bending characteristics and the effective densities of the resonator. Here we first tabulated all the parameters we use in Table 1.
Table 1: Modeling Parameters of Graphene
Parameters for Graphene MHz Resonator: Dimenstion (1.1 um × 0.2 um )
GHz Resonator: Dimenstion (0.1 um × 0.05 um) Thickness 0.34 nm
Mass Density 2.176 kg/m3
(Based on the 2D mass density and the thickness of graphene 0.34 nm) Poisson Ratio 0.17
Young’s Modulus1e12 Pa
Thermal Conductivity 4.83e3 W/(m K)
Thermal Expansion Coefficient 2.6e-6 (1/K)
Heat Capacity (C p) 3.5 J/(kg K)
Parameters for Gold Dimension (0.6um × 0.2um × 0.02um)
Mass Density 19300 kg/m3
Poisson Ratio 0.44
Young’s Modulus7×1010 Pa
Thermal Conductivity 317 W/(m K)
Thermal Expansion Coefficient 14.2×10-6 (1/K)
Heat Capacity (C p) 129 J/(kg K)
Design of the GHz Graphene Resonator
1D Nanoribbon Model
Figure 2:Illustration of 1D beam Continuum Deflected under the Uniform Load (Electrostatic Force)
Because the bending stiffness of the monolayer grapheme is negligible, the grapheme resonator can be treated as a doubly clamped membrane. Furthermore, we simplify our analysis to a 1D string with Length L. The bonding between graphene and gold anchor provides good adhesion.
1.1.1First Eigenmode
According to the geometry from the COMSOL model, the first trial function will be:
?()( )
The stretching stain and axial stain are:
?
∫((?
)) ( ()( ))∫(
?
)
Then we get the total stain energy through the integration:
?
∫∫( )
Here we applied a uniform electrostatic force on the membrane and we assumed that the pressure is P:
∫( )=
The total potential energy will be:
U==
Using principle of virtual work:
Based on the dimension of our device, the area of the parallel plate is :
We finally find the uniform force as a function of deflection:
1.1.2First Eigenfrequency (Rayleigh-Ritz)
An analytical approach can be used to provide good approximations of fundamental and higher order resonant frequencies in systems that conserve energy. If damping is neglected, the Rayleigh-Ritz Methods can be applied to the graphene resonator to provide resonant frequencies based on different trial function. Even rather poor trial functions give reasonably good estimates of the resonant frequency.
From book chapter 10, we can obtain an estimate of using the following equation:
??()
∫∫( )∫( )
( )
1.1.3Second Eigenmode
For the second eigenmode we guess a sine function based on our model and roughly followed the same procedures:
?()
?
∫((?
)) ( ()( ))∫(
?
)?
∫∫( )
∫∫
U==
Using principle of virtual work:
1.1.4Second Eigenfrequency
Using Rayleigh-Ritz Methods:
∫∫( )∫( )
Resonant frequencies for the 1D nanoribbon were calculated theoretically and modeled by COMSOL (2D) before and after optimization. The results are tabulated in Table 2. To design the GHz resonator, we optimize the device dimensions. After changing the dimensions to 100 nm × 50 nm (other parameters remain the same for both cases), the first and the second eigenfrequency reach to 24.137 GHz and 41.806 GHz, respectively.
Due to the simple geometry resulted from the first two eigenmodes, we only calculated from the first trial function in this part. According to the results, it shows that both models match well to the first two eigenmodes. Discrepancies do, however, arise at higher modes. The disagreement that arises in higher modes for the improved device could be attributed to the change in dimension; perhaps the Rayleigh-Ritz method becomes less accurate as the 1D structure departs from the 1D limit, as length is only an order of magnitude different from height and width. This indicates the benefit of using both analytical and numerical methods. Regardless, the decrease in scale clearly improves device performance.
Table 2: Beam Model Eigenmodes
Eigenmode Before OPT
(COMSOL) Before OPT
(Analytical)
After OPT
(COMSOL)
After OPT
(Analytical)
1 149.05 MHz 199.5 MHz 23.91 GHz 24.14 GHz
2 495.44 MHz 345.5 MHz 65.91 GHz 41.81 GHz
3 1042.1 MHz 129.2 GHz
4 1768.1 MHz 213.
5 GHz
5 2657.1 MHz 318.9 GHz
2D-Membrane
When the length and width of the device is comparable, we should model it as a membrane instead of a 1-D beam as we did previously. Hence the more real model is a doubly clamped by the anchors of gold electrodes on two sides and is suspended freely in the middle. Modeling of these two scenarios in COMSOL yielded similar results and can be seen in Table 3. Because of the similarity in the results between beam and membrane the 2D analytical solution is a good approximation of the eigenfrequency.
For the 2-D membrane we assume a trial function which is the two dimensional equivalent of the cosine solution we used for the bent doubly-clamped beam:
?( )( )
?* ()+( )-?
?* ()+( )-?
Boundary conditions of the vertical direction at the ends:
?( )?( )
Boundary conditions of the horizontal direction at the ends:
?( )?( )
All strain terms are defined by
?
(?
)
?
(
?
)
??
∫∫∫( )
∫∫?
Then we integrated to provide an expression for total potential energy in terms the resonant mode ( ) and constants . Minimizing the total potential to get the relationship among and finally using Rayleigh-Ritz method to get the eigenfrequency. Due to limit of time, we are unable to finish this part.
Table 3: Membrane Eigenmodes
Eigenmode Before OPT
(COMSOL) Before OPT
(Analytical)
After OPT
(COMSOL)
After OPT
(Analytical)
1 199.6 MHz 66.73 GHz
2 557.5 MHz 151.5 GHz
3 759.8 MHz 185.5 GHz
4 1113.3 MHz 325.3 GHz
5 1559.2 MHz 368.3 GHz
COMSOL Model
In the paper a continuum model is used for modeling graphene membrane, which matches very well with the experimental data. Hence we also adopt this assumption in our model. The parameters used in COMSOL model are given is Table 1. The resonator is fixed constrained on its two axial ends with gold electrode anchors. We both model for the MHz and GHz graphene resonator with built-in stress taken into account. Furthermore, we numerically find the eigenfrequency, Q factors, and damping ratios.
Figure 3 The first two eigenmodes of optimized geometery. Top Left: The first eigenmode for the beam structure analyzed. Eigenfrequency: 199.5 MHz. Top Right: The first eigenmode for the membrane strucature analyzed. Eigenmode: 200 MHz. Bottom Left: The second eigenmode for the beam structure. Eigenfrequency: 345.5 MHz. Bottom Right: The second eigenmode for the membrane structure. Eigenfrequency: 557 MHz. Beams and membranes showed excellent agreement with eigenfrquency. Additional eigenmodes can be found in the Appendix.
Quality Factor and Damping
One of the design considerations for MEMS Resonators is the Quality Factor (Q). This is the ratio of the total stored energy to the energy dissipated in a single cycle. At a particular oscillation frequency, a higher Q indicates a lower rate of energy dissipation. Consequently, oscillations die out more slowly. Q is defined as:
where is the resonance frequency and is the bandwidth. Bandwidth is defined as the range of frequencies where the oscillation has a power above a certain amplitude threshold, usually defined as half of the maximum energy.
Or alternatively in the COMSOL model, the time-harmonic representation of the fields is more general and includes a complex parameter in the phase:
() ( ?()) ( ?( )
Where the eigenvalue has an imaginary part representing the eigenfrequency and a real part responsible for the damping. It is often more common to use the quality factor, which is derived from the eigenfrequency and damping which are exactly we are using here to determine the quality factor:
A resonator without damping will have an infinite quality factor. Damping sources considered for this resonator were thermoelastic and anchor loss. The device is operating in a vacuum, thus squeeze film damping is not applicable.
Thermoelastic Damping
In any vibrating structure, the strain field causes a change in the internal energy such that compressed region becomes hotter and extended region becomes cooler. The mechanism responsible for thermoelastic damping is the resulting lack of thermal equilibrium between various parts of the vibrating structure. Energy is dissipated when irreversible heat flow driven by the temperature gradient occurs. Vibrations cause alternating tensile and compressive strains to build up on opposite sides of the neutral axis leading to a thermal imbalance. Irreversible heat flow which is driven by the temperature gradient causes vibrational energy to be dissipated. The thermoelastic damping can contribute significantly to Q in MEMS resonators operating in vacuum.
1.1.5Analytical Method
The Q factor for thermal can be expressed as the following:
()
Where E is young’s modulus, α is thermal expansion coefficient, is ambient temperature, is density, is heat capacity at constant pressure, is resonant frequency, and is relaxation time.
( )
( )
()()
For first eigenfrequency
()
For second eigenfrequency
()
1.1.6COMSOL Method
Thermoelastic damping was achieved in COMSOL by adding a frequency dependent heat generating module. The thermal problem and the structural problem must be considered when analyzing thermoelastic damping. When the resonator vibrates heat is generated and causes the resonator to expand and contract in certain regions. This results in a damping effect on the resonator. An eigenfrequency analysis was used to get information on the damping of the system. The increase in temperature due to resonance can be seen in Figure 4.
The temperature increased by a maximum of 3.4349 K in our numerical model. The thermoelastic damping was found to be the dominant damping in the model.
Figure 4: Thermoelastic damping for the first two eigenmodes.
Anchor Damping
Anchor losses result when anchors are stressed as a result of resonator displacement. A fraction of the vibration energy is lost from the resonator though elastic wave propagation into substrate. A typical MEMS resonator is attached in some way to a wafer substrate that is quite large and thick relative to the resonator especially in the graphene case. As the resonator vibrates it puts forces on the substrate, generating stress waves. Thus, a fraction of the vibration energy is lost from the resonator though elastic wave propagation into substrate as shown in the Figure 5.
Figure 5: Illustration of MEMS Resonator loses energy through its anchors The stress waves consist of bulk and surface acoustic waves abbreviated here as (BAW) and (SAW). COMSOL modeling will be useful to analyze this dissipative effect.
1.1.7Analytical Method
Anchor losses can be significant if contributions from other loss mechanisms are negligible, contributing to low values of Q factor.
{
()()}
()
()
( )∫cos(√ ) ( )∫√ cos(√ )
()
1.1.8COMSOL Methodology
Perfectly Matched Layers (PMLs) were used to mimic the effect of an infinite substrate in COMSOL. PMLs simulate wave propagation into an unbounded domain. PML regions were used on the boundary of the gold anchors with material properties of silicon. Essentially the PML acts like an infinite volume of silicon attached to the gold that is a sink for all elastic energy. Eigenfrequency analyses were used to find the anchor loss damping factor. The effect of adding PMLs to our device was an increase in damping.
Damping Summary
COMSOL and analytical methods provide the ability to evaluate the different damping effects. In our model, we investigated thermoelastic, and anchor loss effects. Because the device is operated at vacuum we can neglect the squeeze-film damping effect.
When numerous physical loss mechanisms contribute to overall Q, it can be expressed by each damping components:
The Q thermoelastic, Q anchor and Q total are shown in Table 4.
Table 4: Q Factors
Q thermoelastic Q thermal (Analytical) Q anchor Q total, numerical
1st Eigenmode (MHz) 20970.5 35345 1.43×109 2.10×104
2nd Eigenmode (MHz) 78924.2 204100 1.79×1097.89×104
1st Eigenmode (GHz) 1.08×10632936.1 3.20×104
2nd Eigenmode (GHz) 2.05×106177290 1.63×105 Effect of Residual Stress
The 2D structure of grapheme makes it highly sensitive to tension. It is this property that leads to its favorable tunability with external tension. The dependence on residual stress was analyzed in COMSOL (Figure 6). By increasing the residual stress beyond 4 MPa the original device (non-optimized) was able to achieve GHz second
eigenfrequencies. Achieving the stress needed to reach the gigahertz range becomes a difficult fabrication problem and induces loads into the device that may break or wear the resonator.
Figure 6: Eigenfrequency’s dependence on built-in stress. The circled regions are where the eigenfrequency reaches the GHz frequency range.
Nonlinear Behavior of the System
Graphene has shown strong non-linear damping when fabricated down to the 10 nm scale. This non-linear damping has allowed graphene to achieve the highest recorded Q-factor. It is of particular interest of researchers to know when this onset of non-linearity occurs when fabricating devices.
For a general case, assume a nanomechanical Duffing resonator with linear and nonlinear damping that is driven by a sinusoidal force. Such a resonator can be described by the Euler-Bernoulli equation with nonlinear effects:
? ?
?? ? ? ?
(? )
where m is the effective mass, is its effective spring constant. Effective mass is only related to linear spring constant. ? is the cubic spring constant, or Duffing parameter. The physical manifestation of this parameter is such that a resonator with a negative Duffing term has an attenuated resonant frequency. is the linear damping rate, and ? is the coefficient of nonlinear damping, which increases with the amplitude of oscillation.
From the analytical part using the energy methods to solve for the spring constant, we obtained the force as a function of deflection. Typically, as the deflection c is very small, we can neglect the cubic terms. However, due the ultrahigh young’s modulus and ultrathin thickness of graphene, it makes two terms that are so comparable with small deflection that we cannot neglect either of them. In this case, we will get a nonlinear spring constant where the coefficient of the linear tem is called the linear spring constant and the one preceding the cubic term is Duffing spring constant.
For the first eigenmode,
When c << 0.4 nm, the first term dominates, the deflection goes almost linear as the force increases. However, when c >> 0.4 nm, only second term survives and nonlinear behavior was observed in Figure 7. The onset of linearity effects corresponds to V=44 mV, with estimated vibration amplitude of 1.1 nm which is comparable to our results.
Figure 7: Linear and Nonlinear Regime for the First Eigenmode
It was similar for the second eigenmode except that the linear regime’s limit decreases to 0.2 nm,
When c << 0.2 nm, the first term dominates (linear)
When c >> 0.2 nm, the second term dominates (nonlinear)
Figure 8: Linear and Nonlinear Regime for the Second Eigenmode
Table 5: Summary of the Dynamic Nonlinear Graphene Resonator
Linear Spring Const.
(N/m) Duffing Spring Const.
(N/m3)
Onset of Nonlinearity
(N)
Effective Mass
(kg)
st-14
? ?
?? ? ? ?
(? )
For a more general case, we analyze the Euler-Bernoulli equation with the following assumptions:
1.Measuring time in units of so that the dimensionless time variable is ;
2.Measuring vibration amplitudes in units of length for which a unit-amplitude oscillation doubles the
frequency of the resonator;
3.Dividing the equation by a factor of √ ?.
This will transform the original equation to a simplified one:
?
()
And all parameters will be dimensionless:
?
?
√ ? ; ?
where Q is the quality factor of the resonator.
And by using secular perturbation theory we can obtain one solution (in the limit of a weak linear damping rate with a large Q which is exactly the case for graphene resonator).
The magnitude and phase of the response can be obtained finally as:
( )( )
Then we use matlab to analyze the nonlinearity of the graphene resonator
Figure 9: Drive frequencies effect on amplitude with a damping ratio of 0.1. Left: Amplitude vs drive with a drive frequency of -20 GHz to 20 GHz. Right: Response amplitude as a function of drive amplitude. The circled region marks the onset of non-linearity.
Figure 9 shows the reponse amplitude as a function with drive frequency from -20 GHz to 20 GHz. The coefficient of the nonlinear damping is 0.1. The linear regime reaches up to around 0.8. Increasing the drive amplitude can also increase the resonant frequency. It is expected when we increased the nonlinear damping, the limit of the linear regime will decrease which is around 0.5 for a nonlinear damping coefficient.
Figure 10: Drive frequencies effect on amplitude with a damping coefficient of 0.8. Left: Amplitude vs drive with a drive frequency of -20 GHz to 20 GHz. Right: Response amplitude as a function of drive amplitude. The circled region marks the onset of non-linearity.
0.20.40.60.811.21.41.60
0.5
1
1.5
2
2.5
3
R e s p o n s e A m p l i t u d e
Drive Amplitude
0.10.20.30.40.50.60.70.80.90
0.5
1
1.5
2
R e s p o n s e A m p l i t u d e
Drive Amplitude
Figure 11: Amplitude vs drive frequency in the case where the damping coefficient is 0.
Even though we neglect the nonlinear damping term in the resonator, nonlinear behavior still was followed as increasing the forcing amplitude due to the term relating to Duffing spring constant (? ?). From Figure 11, the resonant frequency is around 20 GHz when g=2.5 and 3.
Conclusions
A tunable MEMs resonator was analyzed in this report for mechanical modes. A resonator with a MHz natural frequency is presented and then designed to achieve GHz Frequencies. This was achieved by reducing the length of the resonator to 100 nm. Beam models and membrane models were developed for the resonator showing little difference between them Quality factors and damping ratios were determined analytically and numerically for thermoelastic damping, and energy loss through the anchors in both the GHz frequency device and MHz frequency device. The effect of stress on eigenfrequency was analyzed. Adding stress has the potential GHz eigenfrequencies for the initial geometry resonator. This method is not advised because of the risk of damaging the device. Furthermore, the onset of nonlinearity was analytically determined for the GHz resonator. The GHz resonator brought forth in this report has an eigenfrequency of 66.73 GHz and a Q-factor of 3.2x104 for its first eigenmode.
References
Thermoelastic Damping
1.Yi, Yun-Bo, and Mohammad A. Matin. "Eigenvalue Solution of Thermoelastic Damping in Beam Resonators Using a Finite Element Analysis." Journal of Vibration and Acoustics 129.4 (2007): 478. Print.
Young’s Modulus
2.Lee, C., X. Wei, J. W. Kysar, and J. Hone. "Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene." Science 321.5887 (2008): 385-88. Print.
Thermal Expansion Coefficient
3.Yoon, Duhee, Young-Woo Son, and Hyeonsik Cheong. "Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy." Nano Letters 11.8 (2011): 3227-231. Print.
Specific Heat Capacity
4.Yi, K. S., D. Kim, and K.-S. Park. "Low-energy Electronic States and Heat Capacities in Graphene Strips." Physical Review B 76.11 (2007). Print.
5.Zhong-Shuai Wu, et al, “Synthesis of Graphene Sheets with High Electrical Conductivity and Good Thermal Stability by Hydrogen Arc Discharge Exfoliation,” ACS Nano, 2009
6.Tovares, Noah, “Reducing Anchor Loss in AlN Contour Mode Resonators,”
7.Senturia, Stephen, Microsystem Design, 2001
8.Reviews of Nonlinear Dynamics and Complexity, Volume 1 edited by Heinz Georg Schuster
A.0Appendices
A.1F irst and second eigenfrequency beam models for original geometery.
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官禄者，为居中正，上合离宫。反应人的禄命官运。第十一宫：福德宫，福德者，位居天仓，牵连地阁。看福禄之运。第十二宫：父母宫，便是额头的日月角。主看父母的福祸疾厄。看面相，形体外貌、精神气质、举止情态皆可一视而察，情人、恋人、夫妻、同事、朋友之间、感情总会有变化的、是相互信任、倾慕也可以从面相看出来。额头眉毛之间只有一道纵纹。这种面相在相学中被称为天柱纹。有此面相的人个性都很顽强。是属于做事不达目的绝不会放弃，对利益也是分得很清楚。一般来讲他们是不做对自己无利的事情。这样的人不但严以律己。同时对别人的要求也非常严格。但还有就是是这种面相的人有一个特征，那就好是这道纵纹平时是不会出现。当他的身心俱疲的时候，这道皱纹才会出现。鼻子的上部这些部位若是出现了数条横纹的人。有此面相特征者对事物都会表现出十足的热情。甚至可以说是充满激情。不仅是做事情又积极又主动。待人处事也是持着一颗平常心。此外，如果是说笑时出现这种皱纹的人。一般性格都是较为温和。缺点就是比较好管别人的事情。也常常为此惹祸上身。 1、男人的眉毛中间稀疏杂乱、毛形逆生，是为乱性之相， 情绪十分不稳定，伴有较重的暴力倾向。-2、双眉过低而压眼，是为心性阴沉扭曲而走极端。-3、女子眉过粗浓，不仅一生婚姻难成，且有妨夫。-4、印堂过窄小，难容两指的人，一生运势不顺且多灾厄。-5、女子双颧露骨而突起，对夫运
字体创意在平面设计中的应用
字体创意在平面设计中的应用 字体创意在平面设计中的应用 字体设计作为视觉传达重要的表现手段之一，既是商业文化的信息载体，也是时代精神的体现者。在平面设计加速发展的当今，要求我们要了解字体的意义和结构，再加上自己的创新意识，把富有创意的字体运用到整个设计中。 一、字体创意性设计在平面中的重要性 人类迈入文明进程最重要的一个标志，是文字的出现。21世纪虽是信息化时代，文字依然以它独特的魅力表现出强烈的视觉感染力。从平面设计来讲，文字是人类社会有史以来最伟大最成功的设计，因为文字是最为简单的设计元素，却又是运用了最为丰富的设计手段。我们应该看到文字的魅力，这些设计品内涵丰富，结构完美，用途广泛，影响深远。在平面设计加速发展的当今，我们把字体直接放到设计的作品里显然是行不通的，这样只会使我们的作品显得腐朽而庸俗。但是当我们充分的了解了字体的意义和构成后，再加上自己的想法进行创新后，把富有创意的字体运用到平面设计中却未尝不可。 二、字体创意在平面中的具体应用 （一）字体创意在招贴设计中的体现 1.字体在招贴广告中的运用 招贴广告与其他的广告媒体一样，在现代经济生活中对加速商品的流通，引导消费观念，活跃市场经济以及文化交流起着积极的作用。招贴广告的基本构成要素是图形、色彩和字体。其中字体又分为标题、正文和广告语。这些都是常见的招贴广告中字体出现的形式。但是字体也常常以图形的形式出现在招贴广告的主体中。设计师通过对字体的分解与重组，或以书体形式，或以满版局部形式，总之可以创造出许多丰富多彩的形式手段。 2.设计师对字体创意性设计的运用 招贴设计史上，以字体创意作为主体内容的优秀广告不胜枚举。包豪斯的莫霍利纳吉曾对自己的设计方法作了这样的概括：“字体设计的材料，其形态大小色彩和编排具有一中强烈的视觉表现力。这些视觉要素的组合可以给要传递的信息内容一个视觉上的实在这意味着通过设计印刷，信息的内容可以通过画面来表达……”。荷兰的设计师桑德伯格也曾将字体即当具体的视觉形式又当文字意义来探索。他把字体看作点、线、面、方向等构成要素。他的设计思想对以后的招贴设计产生了深远的影响。 （二）字体创意在包装中的体现 包装是伴随商品流通出现的产物，作为现代商品不可缺少的构成部分。随着人类社会的发展不断赋予包装新的内涵和使命，现在包装的内涵不仅仅代表了一个承载商品的容器，更代表的是一种引导消费的手段，一种生活方式，一种文化价值的.取向。现代生活节奏的加快，改变了商品的市场营销策略，如除何提高消费者对商品的购买欲，强化商品的品牌意识，已成为现代商品包装与设计的重要课题。除图形、色彩、编排等要素外，包装上的字体设计是传递商品信息、提高企业品牌形象的主要内容。现代购物方式要求商品包装上的文字既是商品说明，又是商品的广告。 （三）字体创意在书籍设计中的体现 书籍装帧是设计是平面设计领域的一部分，在我们日常生活中，好的书籍装帧设计不仅为我们带来了文化知识和信息，同时也创造了一种美的氛围。文字和图片的有效构成是装帧设计的基本手段，其中对文字的处理是一项重要的工作。在书籍装帧中文字既是内容又是形式，它可根据文本内容设计出具有鲜明视觉个性形象的文字，也就是在这里提到的字体创意；也可将文字进行各种恰当的版式编排。有创意性的字体在书籍中往往是用作当书名，当标题。书名是书的灵魂，也是消费者接触到得第一个信息。所以一本书是否具有吸引力，书名很重要，书名的字体设计亦是重要。
字体设计的七种常见类型
1）字体的形象化设计 ●根据字或词的含义添加具体形象。这种形象化的设计手法增加了直观性、趣味性，给人印象深刻。它包括笔画形象化、整体形象化、添加形象和标记形象。 ●形象设计是中国汉字最主要的特征。人类早期的图画文字就是形象化文字。运用这种手法将字图结合，形象地表达字意，有着很好的视觉效果。 ●形象化设计要注意具体形象在文字中的位置及图形与文字之间的关系。以不影响文字的完整性、可识性为前提，起到加强字体表现力的作用。形象的应用要避免生搬硬套，或简单图解化造成的字体格调平庸。（2）字体的意象化设计 ●意象化设计又可称为寓意变化的字体设计。它以强调典型特征或提示的方法对文字加以艺术处理，给人以想像，回味无穷。意象化设计一般不以具体形象穿插配合，而是以文字笔画横、竖、点、撇、捺、挑、钩等偏旁与结构做巧妙变化。这需要对文字设计有独特的理解与创意，于平淡之中见神奇，使内容与形式达到和谐统一。 （3） 字体的装饰化设计 字体的装饰化设计是通过修饰和增加附加纹样，对汉字的本体或背景进行装饰的一种表现方法。它用装饰手法来美化文字，加强文字的内涵，更好地突出主题，使字体效果变得绚丽多彩而富有情趣。字体装饰性设计表现手法很多，有连接、折带、重叠、断笔、扭曲、空心、内线等。（4） 字体的立体设计 ●在平面的字体上, 应用绘画透视的原理来表现文字的立体效果。一般可分平行透视、成角透视、本体透视等。这些手法有很强的表现力，但在绘制上比较复杂。 （5）字体的投影设计 ●利用光线照射在物体上产生阴影的原理，使文字受光线照射产生光影，或把平面字形通过透明物体的遮盖而形成别具一格的艺术效果。可以用光线的方向及投影的角度来设计，能产生多种形式的投影美术字。包括阴影、倒影等形式。 （6）电脑创意字体 ●随着计算机科学的迅速普及，电脑字体也被大量应用到平面设计之中，它既减少了设计制作的时间，又使设计者的创意得到了海阔天空的自由发挥。 ●电脑软件的字库中有几百种字体可供选择应用，如：圆头体、水柱体、综艺体、琥珀体等，将它们直接应用到设计作品中会显得没有个性。需要在电脑中进一步根据不同需要，加工出各种不同的特殊效果，
【PS字体】字体创意设计方法谈
【PS字体】字体创意设计方法谈 从古至今，文字在我们的生活中是必不可少的事物，我们不能想象没有文字的世界将会是怎样。在平面设计中，设计师在文字上所花的心思和功夫最多，因为文字能直观地表达设计师所的意念。在文字上的创造设计，直接反映出平面作品的主题。如设计一幅戴尔笔记本电脑的广告海报，假设海报上没有出现“戴尔”两个文字，即使放上所有戴尔笔记本电脑的图片都不能让人们得知这些电脑是什么品牌。只要写上“戴尔笔记本电脑”几个文字，即使没有产品图片，大家也能知道这张海报的主题。从这个实例中，可以看出文字在平面设计中的重要性。一、字体创意的来源无论汉字，还是拉丁字，任何字体的形成、变化都体现于基本笔形和字形结构，基本笔形和字形结构是字体构成的本质性因素。一种字体构成风格的形成，完全取决于字体基本笔形规范化的字体笔调，正因为以字体笔调构成字体基本笔形的风格定性，才从字体的一笔笔、一画画中渗透出可见的形象性风格。另外，任何一种字体在笔形组合上都向规范化的结构关系展现出字体风格特性，字体中的一笔笔、一个个偏旁部首的组合定势，都以结构上的个性表现出字体的形象性风格。由此我们可以清楚地看出，基本笔形和字形结构不仅是决定字体构成的本质性因素，它更是字体创意的根本源
点。任何字体的创意从这两个根本源点上进行开发，均能从字体的本质性构架上创造出新的形象性字体。从上述的理论中，我们可以分析出，字体创意所要注意的两个重要因素：基本笔形和结构。（一）基本笔形基本笔形是文字笔画形象构成的规范性元素，它是文字符号的“体”的基本定势性决定因素，一种字体中以什么基本笔形组建文字，都由基本笔形的风格定势决定形成某种字体。所以说，所谓字体中的“体”，实质上就是基本笔形所规定“定势”的构成。汉字中的点、横、坚、撇、捺、竖弯勾等基本笔形是任何文字组构的基本元素。拉丁字等文字都具有类似的基本笔形规范而构成字体。因此在字体设计中，字体创意的本质性对象反映为基本笔形的创造。基本笔形中起收笔的变化，横坚画的比例，点、顿角、勾的形象定势，点、撇、捺的运笔规范等，都可以不同的形象观和意识观去变化去表现。图１在字体创意中，基本笔形是字体创意的灵魂所在，好的字体创意的出现或形成，首先是字体基本笔形的出现或形成。因此，字体创意的源点史体现出对基本笔形的变化、变换的探讨。对基本笔形的创造性的探讨，是要从字形组织的基本元素上寻找新的相关性形象。字体基本笔形的开发虽然是一种比较抽象的创造活动，但这种抽象还要来源于现实社会中种种特性的关联，从现实中关联产生的抽象形象，才能在返回现实的过程中获得实质性的效果。（二）
字体创意设计
面设计中，设计师在文字上所花的心思和功夫最多，因为文字能直观地表达设计师所的意念。在文字上的创造设计，直接反映出平面作品的主题。 如设计一幅戴尔笔记本电脑的广告海报，假设海报上没有出现“戴尔”两个文字，即使放上所有戴尔笔记本电脑的图片都不能让人们得知这些电脑是什么品牌。只要写上“戴尔笔记本电脑”几个文字，即使没有产品图片，大家也能知道这张海报的主题。从这个实例中，可以看出文字在平面设计中的重要性。 一、字体创意的来源 无论汉字，还是拉丁字，任何字体的形成、变化都体现于基本笔形和字形结构，基本笔形和字形结构是字体构成的本质性因素。一种字体构成风格的形成，完全取决于字体基本笔形规范化的字体笔调，正因为以字体笔调构成字体基本笔形的风格定性，才从字体的一笔笔、一画画中渗透出可见的形象性风格。 另外，任何一种字体在笔形组合上都向规范化的结构关系展现出字体风格特性，字体中的一笔笔、一个个偏旁部首的组合定势，都以结构上的个性表现出字体的形象性风格。由此我们可以清楚地看出，基本笔形和字形结构不仅是决定字体构成的本质性因素，它更是字体创意的根本源点。任何字体的创意从这两个根本源点上进行开发，均能从字体的本质性构架上创造出新的形象性字体。 从上述的理论中，我们可以分析出，字体创意所要注意的两个重要因素：基本笔形和结构。 （一）基本笔形 基本笔形是文字笔画形象构成的规范性元素，它是文字符号的“体”的基本定势性决定因素，一种字体中以什么基本笔形组建文字，都由基本笔形的风格定势决定形成某种字体。所以说，所谓字体中的“体”，实质上就是基本笔形所规定“定势”的构成。汉字中的点、横、坚、撇、捺、竖弯勾等基本笔形是任何文字组构的基本元素。拉丁字等文字都具有类似的基本笔形规范而构成字体。因此在字体设计中，字体创意的本质性对象反映为基本笔形的创造。基本笔形中起收笔的变化，横坚画的比例，点、顿角、勾的形象定势，点、撇、捺的运笔规范等，都可以不同的形象观和意识观去变化去表现。 在字体创意中，基本笔形是字体创意的灵魂所在，好的字体创意的出现或形成，首先是字体基本笔形的出现或形成。因此，字体创意的源点史体现出对基本笔形的变化、变换的探讨。对基本笔形的创造性的探讨，是要从字形组织的基本元素上寻找新的相关性形象。字体基本笔形的开发虽然是一种比较抽象的创造活动，但这种抽象还要来源于现实社会中种种特性的关联，从现实中关联产生的抽象形象，才能在返回现实的过程中获得实质性的效果。
创意字体设计教案
创意字体设计教案 篇一:有创意的字教案 有创意的字 设计思路: 本节课旨在培养学生了解变体美术字、体验变体美术字的创意能力。融知识性、实用性、趣味性于一体，通过欣赏与分析，设计与制作，合作与交流等课堂教学活动，提高学生对变体美术字的认识和创意的能力。 教学目的: 1、学习变体美术字的基本知识 2、掌握变体美术字的几种变化方法 3、启发和培养学生的想象力、创造力 教学重点: 1、了解掌握变体美术字的变化方法及变化范围 2、试着自己书写变体美术字 教学难点: 对学生分析能力、应变能力和形象思维能力的培养，使他们能根据字体进行灵活合理的变体。 教学过程: 一、视频导入 播放《喜羊羊与灰太狼》动画片开头 生:喜羊羊与灰太狼。
师:动画片好看，它的名字设计的也很有特点。请看展示片头这与我们以前认识到得宋体、黑体美术字有什么区别,展示宋体、黑体字的喜羊羊与灰太狼与之对比 生:动画片片头设计显得更加生动有趣板书生动有趣 师:这种字体是在宋体、黑体美术字的基础上变化而来一种字体，我们叫它变体美术字。这种变化就是变体字的创意设计。今天我们就共同来学习变体美术字的创意设计。板书课题 二、新授过程 (一)变体美术字的应用 1、了解变体美术字在生活中的运用 像这种变体美术字在生活中随处可见，你都在什么地方见过呢, 学生回答老师的问题:衣服商标、商品标志、宣传标语、、、、、师:同学们在实际生活中见到过这样的变体美术字吗,展示生活中的变体美术字 (二) 变体美术字的基本变化规律 1、了解规律 师:老师这儿还有几个变体美术字，大家观察这些字的哪些部位发生了变化, 出示图片 学生说出相应的变化规律就可以了。 教师归纳变化规律 2、争当小设计家 请同学们选择下面的其中一、两个字根据字形、笔画、结构进行变化练习。设计完成以后说一说你的设计思路, 胖、高、电、花、裂、 (三)变体美术字的常见变化方法 1、象形变化
17种设计字体地创意方法
推荐：17种设计字体的创意方法 推荐: 2013/07/23 in 在我们做海报、广告设计中，我们该怎样创造出有魔力的字体紧紧抓住读者的心呢？这篇文章提供的17种创意的字体设计方法也许可以提供给你不一样的灵感与技巧，希望你能在其中找到自己喜欢的:） 复古、时尚、创意字体下载及欣赏→ 1、替换法 替换法是在统一形态的文字元素加入另类不同的图形元素或文字元素。其本质是根据文字的内容意思，用某一形象替代字体的某个部分或某一笔画，这些形象或写实或夸张。将文字的局部替换，是文字的内涵外露，在形象和感官上都增加了一定的艺术感染力。 2、共用法 “笔画公用”是文字图形化创意设计中广泛运用的形式。文字是一种视觉图形，它的线条有着强烈的构成性，可以从单纯的构成角度来看到笔画之间的异同，寻找笔画之间的内在联系，找到他们可以共同利用的条件，把它提取出来合并为一。
3、叠加法 叠加法是将文字的笔画互相重叠或将字与字、字与图形相互重叠的表现手法。叠加能使图形产生三度空间感，通过叠加处理的实行和虚形，增加了设计的内涵和意念，以图形的巧妙组合与表现，使单调的形象丰富起来。
4、分解重构法 分解重构发是将熟悉的文字或图形打散后，通过不同的角度审视并重新组合处理，主要目的是破坏其基本规律并寻求新的设计生命。 总之，平面图形设计的目的是人与人的交流，作为设计者，学习运用符号学工具，会使设计更加有效。在平面设计如此繁杂的今天，把文字图形化运用到设计中，才能使作品具有强烈的视觉冲击力,更便于公众对设计者的作品主题的认识、理解与记忆。 5、俏皮设计法 把横中间拉成圆弧,角也用圆处理,这个方法还有重要一点就是色彩,字体处理上加上色彩的搭配才能作出好的俏皮可爱字体。
14种鼻型图解
26种面型算命图解 侧面观察 1、凸面型 上停位居前额，代表十五至三十岁、父母缘分、思想智慧等事。从侧面观看，这种面型的额头是向后倾斜，表示思想敏捷，下巴向后退缩，不是行动迅速。 但一个人思想、行动都迅速，则其人是一个容易冲动的人 2、凹面型 这种面型的人额头与下巴皆凸出，形成中央鼻子部位凹入 这种人思想、行动都慢；但有忍耐力，不会轻易冲动，给人感觉城府很深，不轻易向他人吐露心声。 3、直面型 直面形是前额与下巴皆没有凸出或退缩，这种面型的人思想与行动都不会急躁或太慢，做任何事都会按部就班，从容面对。 4、额凸下巴退缩 额凸代表思想慢，下巴退缩则代表行动快。 这种面相的人思想慢而行动快，其行动往往未经深思熟虑，所以常有错误的抉择。 5、额斜下巴凸
额斜是思想迅速，下巴凸出是行动缓慢，这种人碰到任何问题都会立即得到思想是回应，但不会马上行动，而会慢慢地行动，大部分人都是这种下巴。 正面观察 正面观察面型的方法较侧面多，有西洋骨相学的三分法，中国的五分法、十分法 其实三分法与五分有许多相同之处，三分法是以人类的思想、行动、物欲享受划分种类，而十分法只是把三分发再细致分划为十种。 三分法 1、思想型 思想型的人其特点是上额广阔而高，下巴尖而小，形成一个倒三角形。 这种形格的人身材一般都属细小、腰部狭窄、手一般略长、面色带白、头发幼而密。 「思想型」这正是推动他们走向成功之路的因素；所以很多科学家、研究家在未成功之前常常会给人行为疯狂、不切实际之感觉。 这种形格的人适宜做科学研究、教育、建筑师、设计师或数学家、分析家等工作。 2、运动型
运动型的人特点就是颧骨高耸，鼻形长而鼻梁有节，腮骨显露，前额一般较低而额上有横纹、面色带黑、头发粗而多、身材高大强壮。其性格特点是忍耐力强，有冒险精神，有责任心，敢作敢为，刻苦耐劳。 这种面型的人最适合从事劳动工作，如工程师、冒险家、探险家、军人、警察或运动员等 3、享受型 享受型的人其特点是颐部园肥，前额较窄小，形成一个正三角形或圆形的面。鼻形较小，鼻头园而有肉，头发幼而疏，面色略微带红，手脚较短，脸部特别肥大，肉多骨少。 这种人处事圆滑，交际手腕强。这种人最适合经商 以上三种形质，只是基本形而已。因为每一个人同样会兼有思想型、运动型及享受型的特征，只是多寡而已，但最好是三种形质发展平衡，这样可工作不忘娱乐，娱乐不忘工作。 如果思想型过重的话，这种人每天只是充满幻想，不肯面对现实，容易引发神经衰落及头痛病等病症，如果再加上整个脸型搭配失宜，如眉粗，眼无神，鼻形短，这样的话，实际谋生能力多有问题。 如果运动型过重的话，则其人精力充沛，行事冲动，喜欢用武力解决问题。如果再加上形质配合不佳，如鼻形不端正，额骨凸露或低，眼神流露等，则其人大多从事低下的劳动工作，只能温饱而已，老来