An innovative specimen holder for liquid TEM

K-kits are sample holders designed to facilitate convenient TEM observation of liquid samples, allowing nanoobjects, aggregates, and agglomerates (NOAAs) in liquid samples to be characterized; with vacuum compatible sealing of liquids in electron-transmitting thickness, K-kits are micro reaction chambers for countless experiments in materials, chemical and biological research.

K-kits are Si-based microchannel devices with silicon nitride windows that allow TEM observation. The seemingly irregular shape is a result of KOH anisotropic wet etching, which is also responsible for forming the rectangular observation window in the middle of the device. The liquid channel is parallel to the window, with openings at both ends.

   Wet and dry mode in sample preparation

The loaded liquid sample is sealed and imaged using TEM in the native liquid environment. (Acceptable image quality with liquid inside the K-kit)
		( NIST traceable polystyrene beads with 100nm in diameter )
A patented liquid drying protocol preserves the original morphology and  physical state of nanomaterials with improved imaging resolution. (Very good image quality, due the the channel being dried out)
There’re two modes of sample preparation Wet and Thin Layer (also called as Dry Mode) available for K-kit. Generally, by using K-kits with larger gap heights (like 2um ones), it will be easily to result in the inner conditions in either fully dried or with a thin liquid layer (with the thickness around 100nm) preserved on the inner walls. Basically, it can be with relatively slight reaction with TEM electron beam, if less amount of liquid remained in the channel. Being able to reduce the liquid bubbling effect by the dry mode, it’s also a unique feature of K-kit that better than the other products in the market.

   The product features of K-kit:  Definitive, quantitative and comprehensive

	K-kit Original physical state	Conventional Aggregated as drying on Cu grid
	(Nanoparticles of CMP Slurry in K-kit and on Cu grid)

			Definitive Direct observation in final product form or relevant media, minimizing artifacts. Quantitative Image-based statistical analysis of aggregation and agglomeration as well as particle concentration. Comprehensive All physicochemical characterization requirements can be addressed.

   Compared with other products in the market

1. Afforable cost for Liquid TEM (Accessible to general researchers and industries)

2. Relatively thinner of liquid layer (resulting in better image quality)
K-kit  (Uni-body, loaded by capillary action)	Special holder + Two chips (Two chips, assembly with a clamping force)
Thinner liquid layer, due to cohesion force	Thicker liquid layer, due to compressive force

Most of the liquid cells currently in the market, which mainly combined by two chips, are not only inconvenient for use, but also very easy to induce a thick liquid layer issue as combining the two chips together, resulting in the TEM images in bad quality and less resolution. Moreover, it will be also with a high risk of leakage when observed in TEM vacuum, if the chips at an improper combination. By K-kit’s unique features of single-chip body and loading by capillary action, we believe that it can be the best solution for liquid-TEM in the current market.

3. The fastest solution for liquid-TEM observation (only 30min required for a K-kit in sample preparation)

	K-kit	90min required for 10 samples Liquid loading and gluing for 10 K-kits (~70min) + vacuum pumping (~20min)
	E-Chip	450min at least for 10 samples One by one; it needs the steps including surface treatment, assembly, leakage detection, and post-cleaning etc. for each. (> 45min for each)

K-kit can be the fastest and easiest solution on the market for liquid-TEM application. It’s suitable for the nanomaterial researches that with multiple test conditions and  industrial applications such like IQC for CMP slurry or CMC in Nanopharmaceuticals etc. especially. In addition, if you have a special holder in house, K-kit also can be considered as the supporting option for saving the time, using on identifying the target samples from your sample group first or the feasibility tests prior to the special holder formally used.

Good resistance to solvents
		After soaking the K-kit sealing glues (Torr Seal) in those chemicals individually for 24 hours, the FTIR analysis results looked perfect.

Reliable liquid loading by capillary action
The viscosity of liquid sample available for K-kit loading can be over 3,000 mPa-s.
(Observed by optical microscope, in transmission mode)
	K-kit is a powerful and convenient tool for liquid-TEM application; as shown the test result, even such sticky the sample C or oily liquid of the sample A, which were all successfully loaded with K-kit.

High image quality in TEM
K-kit usually can be achieved a very good image quality in TEM, whatever it prepared by wet or dry mode.
(Example) By using K-kits to observe the gold reduction process occurred in TEM from AuCl4 solution.  As shown the result in wet mode, the particles with minimum sizes of around 2nm could also be clearly imaged. (by Hitachi HT7700 @100KV)
Magn. x 80K	Magn. x 200K
( K-kit sample: wet mode; gap height: 200nm; SiN membrane: 30nm )

(Example) By using K-kits to observe the gold nanoparticles formed from the reduction process of AuCl4 solution in K-kit.  As shown the TEM images below, the lattice lines of gold particles could be clearly observed by using SiN30nm K-kit. (by FEI Talos TEM @ 200KV)
( K-kit sample: wet mode; gap height: 200nm; SiN membrane: 30nm )

Available for SEM observation

K-kit also can be imaged by SEM, no matter what it prepared in wet or dried mode. Per our test results, the particles (Au) in K-kit with sizes around 10nm could be well imaged by using SEM/ STEM.

(Example) The polystyrene beads in dry mode of K-kit can be also clearly identified by BF/DF/HAADF in SEM/STEM.

Bright Field (BF)                                  Dark Field (DF)                                          HAADF

(K-kit sample: dried mode; gap height: 2000nm; SiN film thickness: 30nm; observed with FEI Helios 400)

Available for EDX analysis
	By pointing the window long side to the detector and tilting the holder at some angles, which could make the EDX analysis achievable on a k-kit.

Tilt Angle = 0		Tilt Angle = 20
(Gap 0.2um K-kit in wet mode; Liquid Sample: AuCl3; TEM: Hitachi HT7700)

Available for TEM electron diffraction analysis
	Example: Gap0.2um/ SiN30nm K-kits; Wet mode (With Liquid) FEI Talos TEM @ 200KV Au nanoparticles was formed by the reduction process from AuCl4 solution in K-kit

NBD (Nano-beam diffraction)

SAD (Selective area diffraction)

Available for multiple loadings (Example of negative-stainned liposomes)

With the unique feature of single-chip structure, K-kit can be possibly applied on multiple loading application, which greatly differed from the other liquid cells by two-chip solution in the market.

The first loading with liquid sample A (Such as liposomes/ LDL)		The K-kit prepared in dry mode for the first liquid		The second loading with liquid sample B (Such like staining solution)		The K-kit in dry mode again for the second liquid
(Example 1) Liposomes after negative staining treatment

	The three TEM images below were gotten from our initial tests, which showing that liposomes could be clearly imaged with K-kits after the treatment of negative staining. The enclosed drug crystals in liposomes can be well identified with K-kit.

Watch K-kit videos online

K-kit User Guide ( Handling with tweezers & Starter box)